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d8dec697-8200-4973-af92-84f118533ca6 Properties of Subatomic Particles Involved in Nuclear Reactions Summary Nuclear reactions involve interactions between subatomic particles, including protons, neutrons, and electrons. Understanding the properties of these particles is crucial for comprehending the behavior and outcomes of nuclear reactions. Protons are positively charged particles found in the nucleus of an atom. They have a relative mass of 1 atomic mass unit (amu) and a charge of +1. Protons determine the atomic number of an element, defining its identity. In nuclear reactions, the number of protons can change, leading to the formation of different elements. Neutrons are neutral particles found in the nucleus of an atom. They have a relative mass of 1 amu but carry no charge. Neutrons provide stability to the nucleus by counteracting the repulsive forces between positively charged protons. In some nuclear reactions, neutrons can be absorbed or emitted, affecting the stability and isotopic composition of the nucleus. Electrons are negatively charged particles that orbit the nucleus of an atom. They have a negligible mass compared to protons and neutrons and a charge of -1. Electrons play a crucial role in chemical reactions, but their involvement in nuclear reactions is limited. They are not directly involved in most nuclear processes. The properties of subatomic particles determine their behavior in nuclear reactions. For example, the positive charge of protons leads to electrostatic repulsion between them. The strong nuclear force, which overcomes this repulsion, holds the nucleus together. The relative mass of protons and neutrons contributes to the overall mass of the nucleus. The mass difference between the reactant and product nuclei in a nuclear reaction can lead to the release or absorption of energy, as described by Einstein's equation E=mc². The absence of charge in neutrons allows them to occupy the nucleus without adding to the electrostatic repulsion. This enhances the stability of the nucleus and contributes to the potential for nuclear reactions. In some nuclear reactions, additional particles such as alpha particles (helium nuclei) or beta particles (electrons or positrons) may be involved. These particles contribute to the transfer of energy and changes in the composition of the nucleus. Understanding the properties of subatomic particles involved in nuclear reactions enables scientists to predict and analyze the behavior of atomic nuclei. It helps explain the formation of elements, the stability of isotopes, and the energy transformations associated with nuclear processes. In summary, the properties of subatomic particles—protons, neutrons, and electrons—affect the behavior and outcomes of nuclear reactions. Protons determine the atomic number, neutrons provide stability, and electrons participate in chemical reactions. The properties of these particles, such as mass, charge, and stability, play vital roles in the interactions within atomic nuclei, leading to the formation of elements and the release or absorption of energy in nuclear reactions.

Problems on Chapter 4 Chapter 4 SABIS Grade 10 Problems Problems on Chapter 4 📝 Lesson 24 📝 Summary Basic Ideas Problems 1. Stoichiometry and Mole-to-Mole Ratio: - Find the number of moles of products formed from a given number of moles of reactants. - Find the number of moles of reactant needed to form a given number of moles of product. Easy Questions: If 2 moles of hydrogen (H2) react with 1 mole of oxygen (O2) to form water (H2O), how many moles of water will be produced? In the reaction of nitrogen (N2) with hydrogen (H2) to form ammonia (NH3), if 1 mole of nitrogen reacts, how many moles of ammonia are produced? If 1 mole of carbon dioxide (CO2) is decomposed into its elements, how many moles of oxygen (O2) are produced? Medium Difficulty Questions: In the reaction of iron (Fe) with oxygen (O2) to form iron(III) oxide (Fe2O3), if 4 moles of iron(III) oxide are produced, how many moles of iron were needed? In the synthesis of ammonia (NH3) from nitrogen (N2) and hydrogen (H2), if you want to produce 10 moles of ammonia, how many moles of nitrogen will you need? In the decomposition of water (H2O) into hydrogen (H2) and oxygen (O2), if you start with 18 moles of water, how many moles of oxygen will be produced? Answers Easy Questions: If 2 moles of hydrogen (H2) react with 1 mole of oxygen (O2) to form water (H2O), how many moles of water will be produced?Answer: 2 moles of water will be produced. (Based on the balanced equation: 2H2 + O2 -> 2H2O) In the reaction of nitrogen (N2) with hydrogen (H2) to form ammonia (NH3), if 1 mole of nitrogen reacts, how many moles of ammonia are produced?Answer: 2 moles of ammonia are produced. (Based on the balanced equation: N2 + 3H2 -> 2NH3) If 1 mole of carbon dioxide (CO2) is decomposed into its elements, how many moles of oxygen (O2) are produced?Answer: 1 mole of oxygen is produced. (Based on the balanced equation: CO2 -> C + O2) Medium Difficulty Questions: In the reaction of iron (Fe) with oxygen (O2) to form iron(III) oxide (Fe2O3), if 4 moles of iron(III) oxide are produced, how many moles of iron were needed?Answer: 8 moles of iron were needed. (Based on the balanced equation: 4Fe + 3O2 -> 2Fe2O3) In the synthesis of ammonia (NH3) from nitrogen (N2) and hydrogen (H2), if you want to produce 10 moles of ammonia, how many moles of nitrogen will you need?Answer: 5 moles of nitrogen are needed. (Based on the balanced equation: N2 + 3H2 -> 2NH3) In the decomposition of water (H2O) into hydrogen (H2) and oxygen (O2), if you start with 18 moles of water, how many moles of oxygen will be produced?Answer: 9 moles of oxygen are produced. (Based on the balanced equation: 2H2O -> 2H2 + O2) 2. Mass Relations and Mass-to-Mass Ratio: - Write the mass ratio of a given reaction. Easy Questions: In the reaction of hydrogen (H2) with oxygen (O2) to form water (H2O), what is the mass ratio of hydrogen to oxygen? Answer: The mass ratio of hydrogen to oxygen is 2g:32g. In the reaction of nitrogen (N2) with hydrogen (H2) to form ammonia (NH3), what is the mass ratio of nitrogen to hydrogen? Answer: The mass ratio of nitrogen to hydrogen is 28g:6g. In the reaction of carbon (C) with oxygen (O2) to form carbon dioxide (CO2), what is the mass ratio of carbon to oxygen? Answer: The mass ratio of carbon to oxygen is 12g:32g. Medium Difficulty Questions: In the reaction of iron (Fe) with oxygen (O2) to form iron(III) oxide (Fe2O3), what is the mass ratio of iron to oxygen? Answer: The mass ratio of iron to oxygen is 112g:96g. In the synthesis of ammonia (NH3) from nitrogen (N2) and hydrogen (H2), what is the mass ratio of nitrogen to hydrogen? Answer: The mass ratio of nitrogen to hydrogen is 28g:6g. In the decomposition of water (H2O) into hydrogen (H2) and oxygen (O2), what is the mass ratio of hydrogen to oxygen? Answer: The mass ratio of hydrogen to oxygen is 2g:32g. - Find the mass of the product formed from a given mass of reactant. Easy Problems: If 4 grams of hydrogen (H2) react with sufficient oxygen (O2) to form water (H2O), what is the mass of water formed? Answer: The molar mass of hydrogen (H2) is 2g/mol and that of water (H2O) is 18g/mol. Therefore, the mass of water formed is (4g H2) * (18g H2O / 2g H2) = 36g of H2O. If 28 grams of nitrogen (N2) react with sufficient hydrogen (H2) to form ammonia (NH3), what is the mass of ammonia formed? Answer: The molar mass of nitrogen (N2) is 28g/mol and that of ammonia (NH3) is 17g/mol. Therefore, the mass of ammonia formed is (28g N2) * (2 * 17g NH3 / 28g N2) = 34g of NH3. If 12 grams of carbon (C) react with sufficient oxygen (O2) to form carbon dioxide (CO2), what is the mass of carbon dioxide formed? Answer: The molar mass of carbon (C) is 12g/mol and that of carbon dioxide (CO2) is 44g/mol. Therefore, the mass of carbon dioxide formed is (12g C) * (44g CO2 / 12g C) = 44g of CO2. Difficult Problems: If 64 grams of sulfur (S8) react with sufficient oxygen (O2) to form sulfur dioxide (SO2), what is the mass of sulfur dioxide formed? Answer: The molar mass of sulfur (S8) is 256g/mol and that of sulfur dioxide (SO2) is 64g/mol. Therefore, the mass of sulfur dioxide formed is (64g S8) * (8 * 64g SO2 / 256g S8) = 128g of SO2. If 56 grams of iron (Fe) react with sufficient oxygen (O2) to form iron(III) oxide (Fe2O3), what is the mass of iron(III) oxide formed? Answer: The molar mass of iron (Fe) is 56g/mol and that of iron(III) oxide (Fe2O3) is 160g/mol. Therefore, the mass of iron(III) oxide formed is (56g Fe) * (160g Fe2O3 / 112g Fe) = 80g of Fe2O3. If 27 grams of aluminum (Al) react with sufficient oxygen (O2) to form aluminum oxide (Al2O3), what is the mass of aluminum oxide formed? Answer: The molar mass of aluminum (Al) is 27g/mol and that of aluminum oxide (Al2O3) is 102g/mol. Therefore, the mass of aluminum oxide formed is (27g Al) * (102g Al2O3 / 54g Al) = 51g of Al2O3. - Find the mass of a given number of moles of a substance. Easy Problems: What is the mass of 2 moles of hydrogen (H2)? Answer: The molar mass of hydrogen (H2) is 2g/mol. Therefore, the mass of 2 moles of hydrogen is (2 moles) * (2g/mol) = 4g. What is the mass of 1 mole of nitrogen (N2)? Answer: The molar mass of nitrogen (N2) is 28g/mol. Therefore, the mass of 1 mole of nitrogen is (1 mole) * (28g/mol) = 28g. What is the mass of 3 moles of carbon (C)? Answer: The molar mass of carbon (C) is 12g/mol. Therefore, the mass of 3 moles of carbon is (3 moles) * (12g/mol) = 36g. Difficult Problems: What is the mass of 0.5 moles of sulfur (S8)? Answer: The molar mass of sulfur (S8) is 256g/mol. Therefore, the mass of 0.5 moles of sulfur is (0.5 moles) * (256g/mol) = 128g. What is the mass of 2.5 moles of iron (Fe)? Answer: The molar mass of iron (Fe) is 56g/mol. Therefore, the mass of 2.5 moles of iron is (2.5 moles) * (56g/mol) = 140g. What is the mass of 1.5 moles of aluminum (Al)? Answer: The molar mass of aluminum (Al) is 27g/mol. Therefore, the mass of 1.5 moles of aluminum is (1.5 moles) * (27g/mol) = 40.5g. 3. Volume Relations and Volume-to-Mole Ratio: - Give the reacting ratios in moles, mass, and volume. Easy Problems: In the reaction of hydrogen (H2) with oxygen (O2) to form water (H2O), what are the reacting ratios in moles, mass, and volume? Answer: The reacting ratios are 2:1 in moles (2 moles of H2 react with 1 mole of O2), 2g:32g in mass, and 44.8L:22.4L in volume. In the reaction of nitrogen (N2) with hydrogen (H2) to form ammonia (NH3), what are the reacting ratios in moles, mass, and volume? Answer: The reacting ratios are 1:3 in moles (1 mole of N2 reacts with 3 moles of H2), 28g:6g in mass, and 22.4L:67.2L in volume. In the reaction of carbon (C) with oxygen (O2) to form carbon dioxide (CO2), what are the reacting ratios in moles, mass, and volume? Answer: The reacting ratios are 1:1 in moles (1 mole of C reacts with 1 mole of O2), 12g:32g in mass, and 22.4L:22.4L in volume. Difficult Problems: In the reaction of sulfur (S8) with oxygen (O2) to form sulfur dioxide (SO2), what are the reacting ratios in moles, mass, and volume? Answer: The reacting ratios are 1:8 in moles (1 mole of S8 reacts with 8 moles of O2), 256g:256g in mass, and 22.4L:179.2L in volume. In the reaction of iron (Fe) with oxygen (O2) to form iron(III) oxide (Fe2O3), what are the reacting ratios in moles, mass, and volume? Answer: The reacting ratios are 4:3 in moles (4 moles of Fe react with 3 moles of O2), 224g:96g in mass. Volume ratio is not applicable as iron is a solid. In the reaction of aluminum (Al) with oxygen (O2) to form aluminum oxide (Al2O3), what are the reacting ratios in moles, mass, and volume? Answer: The reacting ratios are 4:3 in moles (4 moles of Al react with 3 moles of O2), 108g:96g in mass. Volume ratio is not applicable as aluminum is a solid. - Find the volume of one reactant needed to react with a given number of moles of another reactant. Easy Problems: In the reaction of hydrogen (H2) with oxygen (O2) to form water (H2O), what volume of hydrogen is needed to react with 1 mole of oxygen at STP? Answer: The volume of 2 moles of hydrogen at STP is 44.8 L. Therefore, to react with 1 mole of oxygen, 44.8 L of hydrogen is needed. In the reaction of nitrogen (N2) with hydrogen (H2) to form ammonia (NH3), what volume of hydrogen is needed to react with 1 mole of nitrogen at STP? Answer: The volume of 3 moles of hydrogen at STP is 67.2 L. Therefore, to react with 1 mole of nitrogen, 67.2 L of hydrogen is needed. In the reaction of carbon (C) with oxygen (O2) to form carbon dioxide (CO2), what volume of oxygen is needed to react with 1 mole of carbon at STP? Answer: The volume of 1 mole of oxygen at STP is 22.4 L. Therefore, to react with 1 mole of carbon, 22.4 L of oxygen is needed. Difficult Problems: In the reaction of sulfur (S8) with oxygen (O2) to form sulfur dioxide (SO2), what volume of oxygen is needed to react with 0.5 moles of sulfur at STP? Answer: The volume of 8 moles of oxygen at STP is 179.2 L. Therefore, to react with 0.5 moles of sulfur, 89.6 L of oxygen is needed. In the reaction of iron (Fe) with oxygen (O2) to form iron(III) oxide (Fe2O3), what volume of oxygen is needed to react with 2 moles of iron at STP? Answer: The volume of 1.5 moles of oxygen at STP is 33.6 L. Therefore, to react with 2 moles of iron, 33.6 L of oxygen is needed. In the reaction of aluminum (Al) with oxygen (O2) to form aluminum oxide (Al2O3), what volume of oxygen is needed to react with 2 moles of aluminum at STP? Answer: The volume of 1.5 moles of oxygen at STP is 33.6 L. Therefore, to react with 2 moles of aluminum, 33.6 L of oxygen is needed. finding the amount of heat released when a given mass of product is formed from the molar heat of reaction: Easy Problems: In the combustion of methane (CH4), -890.4 kJ of heat is released per mole of CH4 combusted. How much heat is released when 16 g of CH4 (approximately 1 mole) is combusted? Answer: -890.4 kJ of heat is released when 16 g of CH4 is combusted. In the combustion of hydrogen (H2) to form water (H2O), -285.8 kJ of heat is released per mole of H2 combusted. How much heat is released when 2 g of H2 (approximately 1 mole) is combusted? Answer: -285.8 kJ of heat is released when 2 g of H2 is combusted. In the combustion of carbon (C) to form carbon dioxide (CO2), -393.5 kJ of heat is released per mole of C combusted. How much heat is released when 12 g of C (approximately 1 mole) is combusted? Answer: -393.5 kJ of heat is released when 12 g of C is combusted. Difficult Problems: In the combustion of glucose (C6H12O6), -2803 kJ of heat is released per mole of glucose combusted. How much heat is released when 90 g of glucose is combusted? Answer: The molar mass of glucose is approximately 180 g/mol. Therefore, 90 g is approximately 0.5 moles. So, -1401.5 kJ of heat is released when 90 g of glucose is combusted. In the combustion of ethanol (C2H5OH), -1367 kJ of heat is released per mole of ethanol combusted. How much heat is released when 23 g of ethanol is combusted? Answer: The molar mass of ethanol is approximately 46 g/mol. Therefore, 23 g is approximately 0.5 moles. So, -683.5 kJ of heat is released when 23 g of ethanol is combusted. In the combustion of propane (C3H8), -2220 kJ of heat is released per mole of propane combusted. How much heat is released when 22 g of propane is combusted? Answer: The molar mass of propane is approximately 44 g/mol. Therefore, 22 g is approximately 0.5 moles. So, -1110 kJ of heat is released when 22 g of propane is combusted. problems about predicting excess and limiting reagents: Easy Problems: In the reaction of hydrogen (H2) with oxygen (O2) to form water (H2O), if 4 moles of H2 react with 1 mole of O2, which is the limiting reagent? Answer: Oxygen (O2) is the limiting reagent because the reaction requires 2 moles of H2 for every 1 mole of O2. Therefore, there is an excess of H2. In the reaction of nitrogen (N2) with hydrogen (H2) to form ammonia (NH3), if 1 mole of N2 reacts with 2 moles of H2, which is the limiting reagent? Answer: Nitrogen (N2) is the limiting reagent because the reaction requires 3 moles of H2 for every 1 mole of N2. Therefore, there is an excess of H2. In the reaction of carbon (C) with oxygen (O2) to form carbon dioxide (CO2), if 1 mole of C reacts with 1 mole of O2, which is the limiting reagent? Answer: Neither is the limiting reagent because the reaction requires 1 mole of C for every 1 mole of O2. Therefore, there is no excess reagent. Medium Difficulty Problems: In the reaction of sulfur (S8) with oxygen (O2) to form sulfur dioxide (SO2), if 1 mole of S8 reacts with 6 moles of O2, which is the limiting reagent? Answer: Sulfur (S8) is the limiting reagent because the reaction requires 8 moles of O2 for every 1 mole of S8. Therefore, there is an excess of O2. In the reaction of iron (Fe) with oxygen (O2) to form iron(III) oxide (Fe2O3), if 4 moles of Fe react with 2 moles of O2, which is the limiting reagent? Answer: Oxygen (O2) is the limiting reagent because the reaction requires 3 moles of O2 for every 4 moles of Fe. Therefore, there is an excess of Fe. In the reaction of aluminum (Al) with oxygen (O2) to form aluminum oxide (Al2O3), if 4 moles of Al react with 2 moles of O2, which is the limiting reagent? Answer: Aluminum (Al) is the limiting reagent because the reaction requires 3 moles of O2 for every 4 moles of Al. Therefore, there is an excess of O2. Difficult Problems: In the reaction of glucose (C6H12O6) with oxygen (O2) to form carbon dioxide (CO2) and water (H2O), if 1 mole of C6H12O6 reacts with 5 moles of O2, which is the limiting reagent? Answer: Oxygen (O2) is the limiting reagent because the reaction requires 6 moles of O2 for every 1 mole of C6H12O6. Therefore, there is an excess of C6H12O6. In the reaction of ethanol (C2H5OH) with oxygen (O2) to form carbon dioxide (CO2) and water (H2O), if 1 mole of C2H5OH reacts with 2 moles of O2, which is the limiting reagent? Answer: Ethanol (C2H5OH) is the limiting reagent because the reaction requires 3 moles of O2 for every 1 mole of C2H5OH. Therefore, there is an excess of O2. In the reaction of propane (C3H8) with oxygen (O2) to form carbon dioxide (CO2) and water (H2O), if 1 mole of C3H8 reacts with 4 moles of O2, which is the limiting reagent? Answer: Propane (C3H8) is the limiting reagent because the reaction requires 5 moles of O2 for every 1 mole of C3H8. Therefore, there is an excess of O2.

< Back Chapter 13 prerequisite Previous Next 🎆🌟📘 Prerequisites for Chapter 13: Nitrogen and Phosphorus 📘🌟🎆Before diving into 🚀 Chapter 13 , which deals with Nitrogen and Phosphorus , students must have a solid understanding of the following concepts:🔬 1. Basic Atomic Structure 🧪Understand protons, neutrons, and electrons.🔬 2. The Periodic Table 📊Be familiar with the layout of the periodic table and the properties of elements based on their position.🔬 3. Chemical Bonding 💞Understand ionic, covalent, and metallic bonding.🔬 4. Oxidation States ⚖️Understand the common oxidation states of nitrogen and phosphorus.🌈🌟 20 Multiple Choice Questions for Chapter 13: Nitrogen and Phosphorus (Based on Prerequisites) 🌟🌈🤔 Which subatomic particle carries a negative charge? a) Proton b) Neutron c) Electron d) Nucleus🧐 Which element is in Group 15 and Period 2 of the periodic table? a) Nitrogen b) Oxygen c) Carbon d) Phosphorus😯 What type of chemical bond is formed by the sharing of electrons? a) Ionic bond b) Covalent bond c) Metallic bond d) Hydrogen bond🤓 How many valence electrons does nitrogen have? a) 3 b) 5 c) 2 d) 7😲 What is the most common oxidation state of phosphorus? a) +3 b) +5 c) -3 d) +1🧪 Which element is known as a pnictogen? a) Chlorine b) Phosphorus c) Bromine d) Iodine🎈 Which subatomic particle is found in the nucleus and has no charge? a) Proton b) Neutron c) Electron d) Quark🌡️ What type of chemical bond is formed by the transfer of electrons? a) Ionic bond b) Covalent bond c) Metallic bond d) Hydrogen bond💧 How many valence electrons does phosphorus have? a) 3 b) 5 c) 2 d) 7🌟 What is the oxidation state of nitrogen in nitrate (NO3-)? a) +3 b) +5 c) -3 d) +1🍶 Which element is essential for life and is a key component of amino acids and nucleic acids? a) Nitrogen b) Oxygen c) Carbon d) Phosphorus🧲 What is the maximum number of covalent bonds that nitrogen can form? a) 2 b) 3 c) 4 d) 5🎇 What is the most common oxidation state of nitrogen? a) +3 b) +5 c) -3 d) +1🌊 Which element is usedin fertilizers to promote plant growth? a) Nitrogen b) Oxygen c) Phosphorus d) Carbon🌱 Which subatomic particle is found in the nucleus and has a positive charge? a) Proton b) Neutron c) Electron d) Quark🌡️ What type of chemical bond is formed by the attraction between positively charged metal ions and the electrons around them? a) Ionic bond b) Covalent bond c) Metallic bond d) Hydrogen bond🎨 Which element is used in matches and fireworks? a) Chlorine b) Fluorine c) Bromine d) Phosphorus🧊 What is the oxidation state of phosphorus in phosphate (PO4^3-)? a) +3 b) +5 c) -3 d) +1🚀 Which element is a key component of DNA and RNA? a) Nitrogen b) Phosphorus c) Oxygen d) Carbon🧨 What is the term for the outermost electrons in an atom that are involved in chemical bonding? a) Core electrons b) Valence electrons c) Free electrons d) Bonding electrons🌈🌟 Answers 🌟🌈c) Electrona) Nitrogenb) Covalent bondb) 5b) +5b) Phosphorusb) Neutrona) Ionic bondb) 5b) +5a) Nitrogenb) 3c) -3c) Phosphorusa) Protonc) Metallic bondd) Phosphorusb) +5b) Phosphorusb) Valence electrons

506be088-1a1d-45fa-9694-de33a6b8d504 Chemical Change Summary Always produces a new kind of matter, is generally not easily reversible, is usually accompanied by considerable heat change, produces no observable change in mass

d08d3016-c71e-43da-a6c6-54a64b495f78 The Maxwell-Boltzman curve can be used to explain the effect of adding a catalyst on reaction rates. Summary

9fb53fe7-5bc1-4807-b254-f9364c03ac26 Relative magnitude of heat involved in chemical and nuclear changes Summary On the other hand, the heat involved in nuclear changes is orders of magnitude larger than in chemical changes. Nuclear reactions involve changes in the nucleus of an atom, such as nuclear fission or nuclear fusion. These reactions release or absorb an enormous amount of energy due to the conversion of mass into energy, as described by Einstein's famous equation, E = mc^2. The energy released in nuclear changes is millions or billions of times greater than that released in chemical reactions. The heat involved in nuclear reactions is typically measured in millions of electron volts (MeV) or joules (J). The energy released in nuclear fission or fusion reactions can be in the range of millions or billions of joules per mole of reactants or products. For example, the energy released in a typical chemical combustion reaction, such as the burning of a hydrocarbon fuel, is on the order of tens or hundreds of kilojoules per mole. In contrast, the energy released in a nuclear fission reaction, such as the splitting of a uranium nucleus, is on the order of millions of electron volts per nucleus. It's important to note that while nuclear changes involve much larger energy releases, they are also associated with unique challenges and considerations, including the potential for radioactive materials and the requirement for precise control and safety measures. In summary, the relative magnitude of heat involved in chemical and nuclear changes differs significantly. Chemical changes involve relatively small energy changes associated with the breaking and formation of chemical bonds, while nuclear changes involve much larger energy releases due to the conversion of mass into energy. Understanding and quantifying these energy changes are crucial in various scientific, technological, and energy-related applications.

Lesson 48 Chapter 8 SABIS Grade 10 Part 4 Lesson 48 Lesson 4: 🔥 The Energy Stored in a NucleusPart 1: 🔬 Useful InformationSample Question 22 🧲 Discovering the Positron What is a positron?a) It is a particle that forms a neutral atom with one β particle.b) It is as massive as an electron but with a positive charge.c) It is the nucleus of a hydrogen atom.d) It is the nucleus of a helium atom.e) It has a mass of 2 and a charge of 4+. Sample Question 23 🔍 Understanding α Particles What is an α particle?a) It is a particle that forms a neutral atom with one β particle.b) It is an electron with a positive charge.c) It is the nucleus of a hydrogen atom.d) It is the nucleus of a helium atom.e) It has a mass of 2 and a charge of 4+. Part 2: 🌌 Energy Changes in Nuclear ReactionsSample Question 24 🔥 Comparing Heat in Chemical and Nuclear Changes Which of the following is correct about the relative magnitude of the heat involved in nuclear and chemical changes?a) Nuclear changes usually involve energies of tens of kilojoules per mole.b) Chemical reactions usually involve energies of tens of kilojoules per mole.c) Chemical reactions usually involve energies of about a thousand kilojoules per mole.d) Chemical reactions usually involve energies of several million kilojoules per mole.e) Nuclear reactions usually involve energies of tens of millions of kilojoules per mole. Sample Question 25 🧩 Balancing Nuclear Reactions To complete the following equation so it becomes balanced:92𝑈 235 + 0𝑛 1 ➔ 56𝐵𝑎 141 + 36𝐾𝑟 92energya) Three neutrons should be added to the left hand side.b) Three protons should be added to the right hand side.c) Three protons should be added to the left hand side.d) Four hydrogen atoms should be added to the right hand side.e) Three neutrons should be added to the right hand side. Sample Question 26 🔬 Recognizing Nuclear Fission Reactions Which of the following is a nuclear fission reaction?a) 𝐻 + 1𝐻 3 1 2 ➔ 𝐻𝑒 + 0𝑛 1 2 4b) 𝟏𝒆 𝟎 + 𝟗𝟒𝑷𝒖 𝟐𝟑𝟗 ➔ 𝒀 + 𝑪𝒔 + 𝟏𝑯 𝟐 𝟓𝟓 𝟏𝟒𝟔 𝟑𝟗 𝟗𝟏c) UF6(l) ➔ UF6(g).d) C(s) + O2(g) ➔ CO2(g).e) U(s) + 3F2(g) ➔ UF6(g). Sample Question 27 🔒 Conservation in Nuclear Reactions Which of the following is conserved in nuclear reactions?a) Charge.b) Number of nucleons.c) Atoms.d) Kinetic energy of molecules.e) Neutrons. Part 3: 🌐 Mass, a Form of EnergySample Question 28 🧠 Mass of a Nucleus The mass of a nucleus:a) Is determined by adding the masses of the nucleons it contains.b) Is determined by adding the masses of the nucleons it contains and the electrons around it.c) Is determined by subtracting the charge from the mass number.d) Is determined by subtracting the atomic number from the mass number.e) Could be different from the sum of the masses of its nucleons. Sample Question 29 🚀 Mass Lost in Nuclear Reactions In nuclear reactions where mass is lost:a) The equation needs to be balanced properly.b) Charge is also lost.c) The mass will be gained by another reaction.d) The mass reappears as other particles (mass can never be lost or destroyed).e) It changes to energy according to E = mc2. Sample Question 30 🔥 Understanding Nuclear Fusion Reactions In nuclear fusion reactions:a) A large nucleus splits into smaller nuclei.b) Two nuclei come together to form a larger nucleus.c) Is exemplified by 𝑯 + 𝟏𝑯 𝟑 𝟏 𝟐 ➔ 𝟐𝑯𝒆 𝟒 + 𝟎𝒏 𝟏energyd) Is exemplified by 𝑈 + 0𝑛 1 92 235 ➔ 56𝐵𝑎 414 + 𝐾𝑟 + 30𝑛 1 36 92energye) The mass is released as energy.Congratulations! 🎉 You've completed Lesson 4 and delved into the intriguing realm of nuclear energy and reactions. You've explored positrons, α particles, nuclear fission, and fusion. Keep up the amazing work as you venture further into the captivating world of nuclear chemistry! 🌌🚀

c9c08e19-4fdf-4ff4-840b-682f7b0f564c Generally, reactions with low activation energy tend to be fast Summary

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f1304fce-5aef-4433-b888-46896273fcce Reaction Mechanism: reactions rarely proceed in a single step as written. They take place in a series of smaller steps called a reaction mechanism. Summary

Chapter 3 SABIS Grade 10 Part 5 Practice 🔍 Lesson 14 🔍 🔍 Question 1: Decode the molecular formula "2 NH3" and explain the meaning of each letter and digit. 📝 Answer 1: The molecular formula "2 NH3" represents two separate molecules of ammonia (NH3). Each molecule consists of two elements: nitrogen (N) and hydrogen (H). The coefficient "2" indicates that there are two molecules of ammonia. Within each molecule, there is one atom of nitrogen and three atoms of hydrogen chemically bonded together.🔍 Question 2: Interpret the molecular formula "4 C6H12O6" and elaborate on the significance of each letter and digit. 📝 Answer 2: The molecular formula "4 C6H12O6" corresponds to four separate molecules of glucose. Each molecule of glucose contains atoms of carbon (C), hydrogen (H), and oxygen (O). The coefficient "4" indicates that there are four molecules of glucose. Within each molecule, there are six atoms of carbon, twelve atoms of hydrogen, and six atoms of oxygen chemically bonded together. 🔍 Question 3: Understand the meaning of the molecular formula "5 CO2" and provide an explanation for each symbol and number. 📝 Answer 3: The molecular formula "5 CO2" signifies five separate molecules of carbon dioxide (CO2). Each molecule consists of one atom of carbon (C) and two atoms of oxygen (O). The coefficient "5" denotes that there are five molecules of carbon dioxide. Within each molecule, there is one carbon atom and two oxygen atoms chemically bonded together.Fantastic job! Understanding the meaning of molecular formulas with coefficients allows us to determine the composition and arrangement of atoms within a compound. Keep up the great work! ✨😊 🔍 Question 4 : Translate the equation "3 CO2 + 4 H2O → C3H8O3" into words, describing the reaction in terms of molecules and atoms. 📝 Answer 4 : Three molecules of carbon dioxide react with four molecules of water to produce one molecule of C3H8O3. Alternatively, three moles of carbon dioxide react with four moles of water to yield one mole of C3H8O3. 🔍 Question 5 : Interpret the equation "2 Al + 3 Br2 → 2 AlBr3" in words, explaining the reaction in terms of molecules and atoms. 📝 Answer 5 : Two molecules of aluminum react with three molecules of bromine to form two molecules of aluminum bromide. In terms of atoms, two moles of aluminum react with three moles of bromine to produce two moles of aluminum bromide. 🔍 Question 6 : Elaborate on the equation "N2 + 3 H2 → 2 NH3" in words, describing the reaction in terms of molecules and atoms. 📝 Answer 6: One molecule of nitrogen reacts with three molecules of hydrogen to give two molecules of ammonia. Alternatively, one mole of nitrogen reacts with three moles of hydrogen to yield two moles of ammonia. 🔍 Question 7 : 🤔 Determine the atomicity of the following substances: Ne NO HCl NH3 CH4 CO2 📝 Answer: ✅ Here's the atomicity of each substance: Ne: Atomicity of 1. Neon exists as single atoms. 💫 NO: Atomicity of 2. Nitric oxide consists of two atoms bonded together. 🔀 HCl: Atomicity of 2. Hydrochloric acid is composed of two atoms, one each of hydrogen and chlorine, chemically bonded. ⚗️ NH3: Atomicity of 4. Ammonia consists of four atoms, one nitrogen and three hydrogen atoms, chemically bonded together. 🌾 CH4: Atomicity of 5. Methane comprises five atoms, one carbon and four hydrogen atoms, chemically bonded together. 🔥 CO2: Atomicity of 3. Carbon dioxide consists of three atoms, one carbon and two oxygen atoms, chemically bonded together. ☁️ Understanding the atomicity of substances helps us comprehend the arrangement and composition of atoms within a molecule. Well done! 🎉👍 🔍 Question 8: 💡 Find the simplest formula for each of the following substances: a) Benzene: C6H6 b) Ethane: C2H6 c) Sodium nitrate: NaNO3 d) Sand: SiO2 e) Vinegar: CH3COOH f) Fructose: C6H12O6 📝 Answer: ✅ Here are the simplest formulas for each substance: a) Benzene: CH. The simplest formula of benzene represents one carbon atom and one hydrogen atom in each repeating unit of the molecule. 🌺 b) Ethane: CH3. The simplest formula of ethane consists of one carbon atom bonded to three hydrogen atoms. 🚀 c) Sodium nitrate: NaNO3. The given formula already represents the simplest ratio of atoms in sodium nitrate. 🔩 d) Sand: SiO2. The simplest formula of sand indicates that each silicon atom is bonded to two oxygen atoms. 🏖️ e) Vinegar: CH2O. The simplest formula of vinegar reveals one carbon atom, two hydrogen atoms, and one oxygen atom in each molecule. 🍷 f) Fructose: CH2O. The simplest formula of fructose displays one carbon atom, two hydrogen atoms, and one oxygen atom per molecule. 🍏 Knowing the simplest formulas helps us understand the fundamental composition of substances. Great job! 🎉👍 🔍 Question 9: 💡 Name or write the formula for the following binary compounds: I. Write the formula of: a) Sulphur dioxide: SO2 b) Phosphorus pentachloride: PCl5 c) Dinitrogen pentoxide: N2O5 II. Give the name of: a) HI: Hydrogen iodide b) CCl4: Carbon tetrachloride c) NO2: Nitrogen dioxide 📝 Answer: ✅ Here are the formulas and names of the given binary compounds: I. Write the formula of: a) Sulphur dioxide: SO2 b) Phosphorus pentachloride: PCl5 c) Dinitrogen pentoxide: N2O5 II. Give the name of: a) HI: Hydrogen iodide b) CCl4: Carbon tetrachloride c) NO2: Nitrogen dioxide Understanding how to name and write the formulas of binary compounds is crucial for communicating and identifying different substances. Well done! 🎉👍 🔍 Question 10: 💡 Name or write the formula for the following binary compounds: I. Write the formula of: a) Potassium oxide b) Aluminum chloride c) Carbon monoxide II. Give the name of: a) SO3 b) MgBr2 c) H2S 📝 Answer: ✅ Here are the formulas and names of the additional binary compounds: I. Write the formula of: a) Potassium oxide: K2O b) Aluminum chloride: AlCl3 c) Carbon monoxide: CO II. Give the name of: a) SO3: Sulfur trioxide b) MgBr2: Magnesium bromide c) H2S: Hydrogen sulfide Great job! Naming and writing formulas for binary compounds is an essential skill in chemistry. Keep up the excellent work! 🎉👍 Here's a brief explanation of the questions 11-14 concept: In chemistry, we often use a unit called atomic mass unit (amu) to measure the mass of atoms. Atomic mass unit is a way to express the relative mass of an atom compared to a reference atom, which is carbon-12 (C-12). The atomic mass unit is defined as 1/12th of the mass of a carbon-12 atom. Knowing the mass of atoms in amu is important because it helps us understand the composition of different elements and compounds. In the following questions (11-14), we will explore the mass of specific atoms and determine their mass in atomic mass units (amu). 🔍 Question 11: 💡 Determine the mass in atomic mass units (amu) for the following atoms: a) What is the mass of an atom of silver in amu? (Answer: 108 amu) 📝 Answer 11: ✅ The mass of an atom of silver is 108 amu. 🔍 Question 12: 💡 Find the mass in amu for the following atoms: a) What is the mass of an atom of oxygen in amu? b) Determine the mass of a carbon atom in amu. c) Calculate the mass of a helium atom in amu. 📝 Answer 12: a) The mass of an atom of oxygen is approximately 16 amu. b) A carbon atom has a mass of about 12 amu. c) The mass of a helium atom is around 4 amu. 🔍 Question 13: 💡 Identify the mass in amu for the given atoms: a) What is the mass of an atom of hydrogen in amu? b) Determine the mass of a nitrogen atom in amu. c) Calculate the mass of a sulfur atom in amu. 📝 Answer 13: a) An atom of hydrogen has a mass of approximately 1 amu. b) The mass of a nitrogen atom is about 14 amu. c) A sulfur atom has a mass of around 32 amu. 🔍 Question 14: 💡 Find the mass in atomic mass units (amu) for the following atoms: a) What is the mass of an atom of gold in amu? b) Determine the mass of a chlorine atom in amu. c) Calculate the mass of a lithium atom in amu. 📝 Answer 14: a) The mass of an atom of gold is approximately 197 amu. b) A chlorine atom has a mass of about 35.5 amu. c) The mass of a lithium atom is around 7 amu. Well done! Understanding the mass of atoms in atomic mass units (amu) is essential in chemistry. Keep up the great work! 🎉👍 Here's a brief explanation of the questions 15-18 concept: Concept Explanation: In chemistry, we often work with large quantities of atoms. Avogadro's number, which is approximately 6.02 × 10^23, represents the number of atoms or molecules present in one mole of a substance. It allows us to relate the number of particles to the mass of a substance. Knowing the mass of a specific number of atoms is important as it helps us understand the total mass of a given element or compound. By using the atomic mass of an element, we can calculate the mass of a specified number of atoms. 🔍 Question 15: What is the mass of 6.02 × 10^23 atoms of oxygen in grams? (Atomic mass of oxygen = 16 g/mol) 📝 Answer 15: The mass of 6.02 × 10^23 atoms of oxygen is equal to the atomic mass of oxygen, which is 16 grams per mole. Therefore, the mass of 6.02 × 10^23 atoms of oxygen is also 16 grams. 🔍 Question 16: Calculate the mass of 6.02 × 10^23 atoms of carbon in grams. (Atomic mass of carbon = 12 g/mol) 📝 Answer 16: The mass of 6.02 × 10^23 atoms of carbon can be determined using the atomic mass of carbon, which is 12 grams per mole. Therefore, the mass of 6.02 × 10^23 atoms of carbon is also 12 grams. 🔍 Question 17: Determine the mass of 6.02 × 10^23 atoms of hydrogen in grams. (Atomic mass of hydrogen = 1 g/mol) 📝 Answer 17: The mass of 6.02 × 10^23 atoms of hydrogen can be calculated using the atomic mass of hydrogen, which is 1 gram per mole. Therefore, the mass of 6.02 × 10^23 atoms of hydrogen is also 1 gram. 🔍 Question 18: Find the mass of 6.02 × 10^23 atoms of nitrogen in grams. (Atomic mass of nitrogen = 14 g/mol) 📝 Answer 18: The mass of 6.02 × 10^23 atoms of nitrogen is determined by the atomic mass of nitrogen, which is 14 grams per mole. Therefore, the mass of 6.02 × 10^23 atoms of nitrogen is also 14 grams. Concept Explanation: The concept of molar mass is crucial in chemistry as it allows us to determine the mass of one mole of a substance. Molar mass is expressed in grams per mole (g/mol) and represents the mass of the element or compound in atomic mass units (amu) when scaled up to one mole. 🔍 Question 19: Calculate the mass of 1 mole of oxygen in grams. (Atomic mass of oxygen = 16 g/mol) 📝 Answer 19: The mass of 1 mole of oxygen is equal to its molar mass, which is 16 grams per mole. Therefore, the mass of 1 mole of oxygen is 16 grams. 🔍 Question 20: Find the mass of 1 mole of carbon in grams. (Atomic mass of carbon = 12 g/mol) 📝 Answer 20: The mass of 1 mole of carbon is determined by its molar mass, which is 12 grams per mole. Hence, the mass of 1 mole of carbon is 12 grams. 🔍 Question 21: Determine the mass of 1 mole of hydrogen in grams. (Atomic mass of hydrogen = 1 g/mol) 📝 Answer 21: The mass of 1 mole of hydrogen is calculated using its molar mass, which is 1 gram per mole. Consequently, the mass of 1 mole of hydrogen is 1 gram. 🔍 Question 22: Calculate the mass of 1 mole of nitrogen in grams. (Atomic mass of nitrogen = 14 g/mol) 📝 Answer 22: The mass of 1 mole of nitrogen can be found using its molar mass, which is 14 grams per mole. Therefore, the mass of 1 mole of nitrogen is 14 grams. Concept Explanation: When given the mass of a substance, we can determine the number of moles and the number of atoms present. This involves using the molar mass of the substance and Avogadro's number. To find the number of moles, we divide the given mass by the molar mass of the substance. The molar mass represents the mass of one mole of the substance in grams. To find the number of atoms, we multiply the number of moles by Avogadro's number and the atomicity of the substance. The atomicity refers to the number of atoms in one molecule of the substance. 🔍 Question 23: Calculate the number of moles and the number of atoms in 8.2 g of carbon dioxide (CO2). Given: mCO2 = 8.2 g, atomicity of CO2 = 3. 📝 Answer 23: To find the number of moles of CO2, we divide the given mass by its molar mass. The molar mass of CO2 is approximately 44 g/mol. nCO2 = mCO2 / MCO2 = 8.2 g / 44 g/mol ≈ 0.186 moles To find the number of atoms, we multiply the number of moles by Avogadro's number (6.02 × 10^23) and the atomicity of CO2 (3). Number of atoms = nCO2 × (6.02 × 10^23) × atomicity = 0.186 × (6.02 × 10^23) × 3 ≈ 3.37 × 10^23 atoms 🔍 Question 24: Determine the number of moles and the number of atoms in 25 g of water (H2O). Given: mH2O = 25 g, atomicity of H2O = 3. 📝 Answer 24: The molar mass of water (H2O) is approximately 18 g/mol. To find the number of moles: nH2O = mH2O / MH2O = 25 g / 18 g/mol ≈ 1.39 moles To find the number of atoms, we multiply the number of moles by Avogadro's number (6.02 × 10^23) and the atomicity of H2O (3). Number of atoms = nH2O × (6.02 × 10^23) × atomicity = 1.39 × (6.02 × 10^23) × 3 ≈ 2.51 × 10^24 atoms 🔍 Question 25: Calculate the number of moles and the number of atoms in 15 g of methane (CH4). Given: mCH4 = 15 g, atomicity of CH4 = 5. 📝 Answer 25: The molar mass of methane (CH4) is approximately 16 g/mol. To find the number of moles: nCH4 = mCH4 / MCH4 = 15 g / 16 g/mol ≈ 0.938 moles To find the number of atoms, we multiply the number of moles by Avogadro's number (6.02 × 10^23) and the atomicity of CH4 (5). Number of atoms = nCH4 × (6.02 × 10^23) × atomicity = 0.938 × (6.02 × 10^23) × 5 ≈ 2.83 × 10^24 atoms Concept Explanation: When given the mass of a substance, we can calculate the number of moles, molecules, and atoms present. This involves using the molar mass of the substance and Avogadro's number. To find the number of moles, we divide the given mass by the molar mass of the substance. The molar mass represents the mass of one mole of the substance in grams. To calculate the number of molecules, we multiply the number of moles by Avogadro's number (6.02 × 10^23). This gives us the number of molecules present in the given mass. To determine the number of atoms, we multiply the number of molecules by the atomicity of the substance. The atomicity refers to the number of atoms in one molecule of the substance. 🔍 Question 26: Calculate the number of moles, molecules, and atoms in 3.50 g of hydrogen (H2). Given: mH2 = 3.50 g. 📝 Answer 26: To find the number of moles of hydrogen, we divide the given mass by its molar mass. The molar mass of hydrogen is approximately 2 g/mol. nH2 = mH2 / MH2 = 3.50 g / 2 g/mol = 1.75 moles To calculate the number of molecules, we multiply the number of moles by Avogadro's number (6.02 × 10^23). Number of molecules = nH2 × (6.02 × 10^23) = 1.75 × (6.02 × 10^23) = 1.05 × 10^24 molecules To determine the number of atoms, we multiply the number of molecules by the atomicity of hydrogen (2). Number of atoms = number of molecules × atomicity = 1.05 × 10^24 × 2 = 2.10 × 10^24 atoms 🔍 Question 27: Find the number of moles, molecules, and atoms in 5.60 g of carbon dioxide (CO2). Given: mCO2 = 5.60 g. 📝 Answer 27: The molar mass of carbon dioxide (CO2) is approximately 44 g/mol. To find the number of moles: nCO2 = mCO2 / MCO2 = 5.60 g / 44 g/mol = 0.127 moles To calculate the number of molecules, we multiply the number of moles by Avogadro's number (6.02 × 10^23). Number of molecules = nCO2 × (6.02 × 10^23) = 0.127 × (6.02 × 10^23) = 7.65 × 10^22 molecules To determine the number of atoms, we multiply the number of molecules by the atomicity of CO2 (3). Number of atoms = number of molecules × atomicity = 7.65 × 10^22 × 3 = 2.30 × 10^23 atoms 🔍 Question 28: Calculate the number of moles, molecules, and atoms in 4.80 g of water (H2O). Given: mH2O = 4.80 g. 📝 Answer 28: The molar mass of water (H2O) is approximately 18 g/mol. To find the number of moles: nH2O = mH2O / MH2O = 4.80 g / 18 g/mol = 0.267 moles To calculate the number of molecules, we multiply the number of moles by Avogadro's number (6.02 × 10^23). Number of molecules = nH2O × (6.02 × 10^23) = 0.267 × (6.02 × 10^23) = 1.61 × 10^23 molecules To determine the number of atoms, we multiply the number of molecules by the atomicity of water (3). Number of atoms = number of molecules × atomicity = 1.61 × 10^23 × 3 = 4.83 × 10^23 atoms Concept Explanation: We can calculate the number of moles and the mass of a given number of molecules of a substance. This involves using Avogadro's number and the molar mass of the substance. To find the number of moles, we divide the given number of molecules by Avogadro's number (6.02 × 10^23). This gives us the quantity in moles. To calculate the mass, we multiply the number of moles by the molar mass of the substance. The molar mass represents the mass of one mole of the substance in grams. 🔍 Question 29: How many moles do 1.20 × 10^23 molecules of carbon dioxide (CO2) represent? Calculate the mass of the given quantity. Given: 1.20 × 10^23 molecules of CO2. 📝 Answer 29: To find the number of moles, we divide the given number of molecules by Avogadro's number. Number of moles = (1.20 × 10^23) / (6.02 × 10^23) = 0.199 moles To calculate the mass, we multiply the number of moles by the molar mass of carbon dioxide (CO2). Mass = number of moles × molar mass = 0.199 moles × (12 + 16 + 16) g/mol = 15.9 g 🔍 Question 30: Determine the number of moles represented by 4.50 × 10^24 molecules of water (H2O). Calculate the mass of the given quantity. Given: 4.50 × 10^24 molecules of H2O. 📝 Answer 30: To find the number of moles, we divide the given number of molecules by Avogadro's number. Number of moles = (4.50 × 10^24) / (6.02 × 10^23) = 7.48 moles To calculate the mass, we multiply the number of moles by the molar mass of water (H2O). Mass = number of moles × molar mass = 7.48 moles × (2 + 16) g/mol = 179 g 🔍 Question 31: Find the number of moles represented by 2.75 × 10^22 molecules of methane (CH4). Calculate the mass of the given quantity. Given: 2.75 × 10^22 molecules of CH4. 📝 Answer 31: To find the number of moles, we divide the given number of molecules by Avogadro's number. Number of moles = (2.75 × 10^22) / (6.02 × 10^23) = 0.0456 moles To calculate the mass, we multiply the number of moles by the molar mass of methane (CH4). Mass = number of moles × molar mass = 0.0456 moles × (12 + 4) g/mol = 2.51 g Concept Explanation: We can calculate the number of molecules and atoms in a given number of moles of a substance. This involves using Avogadro's number and the concept of atomicity. To find the number of molecules, we multiply the number of moles by Avogadro's number (6.02 × 10^23). This gives us the quantity in molecules. To calculate the number of atoms, we multiply the number of molecules by the atomicity, which represents the number of atoms in one molecule of the substance. 🔍 Question 32: Calculate the number of molecules and atoms in 2.5 moles of CO2 (carbon dioxide). Given: 2.5 moles of CO2. 📝 Answer 32: To find the number of molecules, we multiply the number of moles by Avogadro's number. Number of molecules = 2.5 moles × 6.02 × 10^23 molecules/mole = 1.51 × 10^24 molecules To calculate the number of atoms, we multiply the number of molecules by the atomicity of CO2, which is 3 (1 carbon atom and 2 oxygen atoms per molecule). Number of atoms = 1.51 × 10^24 molecules × 3 atoms/molecule = 4.53 × 10^24 atoms 🔍 Question 33: Find the number of molecules and atoms in 0.75 moles of H2O (water). Given: 0.75 moles of H2O. 📝 Answer 33: To find the number of molecules, we multiply the number of moles by Avogadro's number. Number of molecules = 0.75 moles × 6.02 × 10^23 molecules/mole = 4.52 × 10^23 molecules To calculate the number of atoms, we multiply the number of molecules by the atomicity of H2O, which is 3 (2 hydrogen atoms and 1 oxygen atom per molecule). Number of atoms = 4.52 × 10^23 molecules × 3 atoms/molecule = 1.36 × 10^24 atoms 🔍 Question 34: Determine the number of molecules and atoms in 1.2 moles of O2 (oxygen gas). Given: 1.2 moles of O2. 📝 Answer 34: To find the number of molecules, we multiply the number of moles by Avogadro's number. Number of molecules = 1.2 moles × 6.02 × 10^23 molecules/mole = 7.22 × 10^23 molecules To calculate the number of atoms, we multiply the number of molecules by the atomicity of O2, which is 2 (2 oxygen atoms per molecule). Number of atoms = 7.22 × 10^23 molecules × 2 atoms/molecule = 1.44 × 10^24 atoms Well done! Understanding the relationship between moles, molecules, and atoms helps us quantify and comprehend the vastness of the microscopic world. Keep up the fantastic work! 🎉👏 Concept Explanation: We can determine the number of moles and the number of molecules in a given volume of a substance at STP (Standard Temperature and Pressure). This involves using the volume of the substance and the conversion factor of 22.4 liters per mole at STP. To find the number of moles, we divide the given volume by the molar volume at STP (22.4 liters/mol). This gives us the quantity in moles. To calculate the number of molecules, we multiply the number of moles by Avogadro's number (6.02 × 10^23 molecules/mol). This gives us the quantity in molecules. 🔍 Question 35: Calculate the number of moles and the number of molecules in 840 cm³ of oxygen gas (O₂) at STP. Given: V of O₂ = 840 cm³ at STP. 📝 Answer 35: To find the number of moles, we convert the given volume to liters by dividing it by 1000 (since 1 liter = 1000 cm³), and then divide by the molar volume at STP. V = 840 cm³ = 0.840 liters Number of moles = V / molar volume at STP = 0.840 L / 22.4 L/mol = 0.0375 moles To calculate the number of molecules, we multiply the number of moles by Avogadro's number. Number of molecules = 0.0375 moles × 6.02 × 10^23 molecules/mol = 2.26 × 10^22 molecules 🔍 Question 36: Determine the number of moles and the number of molecules in 5.60 liters of hydrogen gas (H₂) at STP. Given: V of H₂ = 5.60 liters at STP. 📝 Answer 36: To find the number of moles, we divide the given volume by the molar volume at STP. Number of moles = V / molar volume at STP = 5.60 L / 22.4 L/mol = 0.250 moles To calculate the number of molecules, we multiply the number of moles by Avogadro's number. Number of molecules = 0.250 moles × 6.02 × 10^23 molecules/mol = 1.51 × 10^23 molecules 🔍 Question 37: Find the number of moles and the number of molecules in 4.50 dm³ of nitrogen gas (N₂) at STP. Given: V of N₂ = 4.50 dm³ at STP. 📝 Answer 37: To find the number of moles, we divide the given volume by the molar volume at STP. Number of moles = V / molar volume at STP = 4.50 dm³ / 22.4 dm³/mol = 0.201 moles To calculate the number of molecules, we multiply the number of moles by Avogadro's number. Number of molecules = 0.201 moles × 6.02 × 10^23 molecules/mol = 1.21 × 10^23 molecules Great job! Understanding the relationship between volume, moles, and molecules at STP helps us relate macroscopic measurements to the microscopic world of atoms and molecules. Keep up the excellent work! 🎉👍 Concept Explanation: When comparing the number of atoms in given masses of two elements, we need to calculate the number of moles for each element using their respective masses and molar masses. Then, we can determine which element has a higher number of atoms by comparing the number of moles.To find the number of moles, we divide the given mass by the molar mass of each element. The molar mass represents the mass of one mole of a substance.Once we have the number of moles for each element, we can compare them. The element with a higher number of moles will have more atoms.🔍 Question 38: Compare the number of atoms in 5.0 grams of oxygen (O) and 8.0 grams of sulfur (S). Given: mO = 5.0 g and mS = 8.0 g.📝 Answer 38: To determine the number of atoms, we first calculate the number of moles for each element.nO = mO / MO = 5.0 g / 16.0 g/mol = 0.3125 moles nS = mS / MS = 8.0 g / 32.0 g/mol = 0.25 molesSince nO > nS, 5.0 grams of oxygen has more atoms than 8.0 grams of sulfur.IF THE QUESTION REQUIRES FINDING THE NUMBER OF ATOMS OF EACH ELEMENT:nO = mO / MO = 5.0 g / 16.0 g/mol = 0.3125 moles nS = mS / MS = 8.0 g / 32.0 g/mol = 0.25 molesNumber of oxygen atoms = nO × NA = 0.3125 moles × 6.02 × 10^23 atoms/mol = 1.88 × 10^23 atoms Number of sulfur atoms = nS × NA = 0.25 moles × 6.02 × 10^23 atoms/mol = 1.51 × 10^23 atomsTherefore, 5.0 grams of oxygen has more atoms than 8.0 grams of sulfur.🔍 Question 39: Which has more atoms, 10.0 grams of carbon (C) or 15.0 grams of nitrogen (N)? Given: mC = 10.0 g and mN = 15.0 g.📝 Answer 39: To find the number of atoms, we calculate the number of moles for each element.nC = mC / MC = 10.0 g / 12.0 g/mol = 0.833 moles nN = mN / MN = 15.0 g / 14.0 g/mol = 1.07 molesSince nN > nC, 15.0 grams of nitrogen has more atoms than 10.0 grams of carbon.IF THE QUESTION REQUIRES FINDING THE NUMBER OF ATOMS OF EACH ELEMENT:nC = mC / MC = 10.0 g / 12.0 g/mol = 0.833 moles nN = mN / MN = 15.0 g / 14.0 g/mol = 1.07 molesNumber of carbon atoms = nC × NA = 0.833 moles × 6.02 × 10^23 atoms/mol = 5.01 × 10^23 atoms Number of nitrogen atoms = nN × NA = 1.07 moles × 6.02 × 10^23 atoms/mol = 6.44 × 10^23 atomsHence, 15.0 grams of nitrogen has more atoms than 10.0 grams of carbon.🔍 Question 40: Compare the number of atoms in 3.5 grams of hydrogen (H) and 2.0 grams of chlorine (Cl). Given: mH = 3.5 g and mCl = 2.0 g.📝 Answer 40: To determine the number of atoms, we first calculate the number of moles for each element.nH = mH / MH = 3.5 g / 1.0 g/mol = 3.5 moles nCl = mCl / MCl = 2.0 g / 35.5 g/mol = 0.0563 molesSince nH > nCl, 3.5 grams of hydrogen has more atoms than 2.0 grams of chlorine.IF THE QUESTION REQUIRES FINDING THE NUMBER OF ATOMS OF EACH ELEMENT:nH = mH / MH = 3.5 g / 1.0 g/mol = 3.5 moles nCl = mCl / MCl = 2.0 g / 35.5 g/mol = 0.0563 molesNumber of hydrogen atoms = nH × NA = 3.5 moles × 6.02 × 10^23 atoms/mol = 2.11 × 10^24 atoms Number of chlorine atoms = nCl × NA = 0.0563 moles × 6.02 × 10^23 atoms/mol = 3.39 × 10^22 atomsTherefore, 3.5 grams of hydrogen has more atoms than 2.0 grams of chlorine.Great job! Understanding the relationship between mass, moles, and the number of atoms helps us compare quantities of different elements and their atomic compositions. Keep up the fantastic work! 🎉👍 Concept Explanation: To find the molecular formula of a compound given its molar mass and simplest formula, we need to determine the value of "n" in the molecular formula (CH)n. "n" represents the number of empirical formula units present in one molecule of the compound. The molar mass of the compound can be calculated by multiplying the molar mass of the empirical formula by "n". By equating this molar mass to the given molar mass, we can solve for "n". Once we have determined the value of "n", we can write the molecular formula of the compound by multiplying the empirical formula by "n". 🔍 Question 41: A compound has a molar mass of 108 g/mol. If its simplest formula is NH2, determine its molecular formula. 📝 Answer 41: Given: Simplest formula = NH2, Molar mass = 108 g/mol To find the molecular formula, we need to determine the value of "n" in the molecular formula (NH2)n. Molar mass = empirical formula mass × n 108 g/mol = (14 + 2) g/mol × n 108 g/mol = 16 g/mol × n n = 108 g/mol / 16 g/mol n = 6.75 Since "n" should be an integer, we round it to the nearest whole number, which is 7. The molecular formula of the compound is (NH2)7. IF THE QUESTION REQUIRES FINDING THE MOLECULAR FORMULA OF ANOTHER COMPOUND: Follow the same procedure by substituting the given simplest formula and molar mass into the calculations. 🔍 Question 42: A compound has a molar mass of 180 g/mol. If its simplest formula is C2H4O, what is its molecular formula? 📝 Answer 42: Given: Simplest formula = C2H4O, Molar mass = 180 g/mol To find the molecular formula, we need to determine the value of "n" in the molecular formula (C2H4O)n. Molar mass = empirical formula mass × n 180 g/mol = (12 + 4 + 16) g/mol × n 180 g/mol = 32 g/mol × n n = 180 g/mol / 32 g/mol n = 5.625 Since "n" should be an integer, we round it to the nearest whole number, which is 6. The molecular formula of the compound is (C2H4O)6. Great work! Finding the molecular formula based on the molar mass and simplest formula allows us to determine the actual composition of a compound. Keep up the excellent progress! 🎉👍 Concept Explanation: To find the molar mass of a compound given its simplest formula and the number of carbon atoms per molecule, we need to determine the molecular formula of the compound first. The molecular formula represents the actual number and types of atoms in one molecule of the compound. In this case, the simplest formula is CClH2, and we know that there are two carbon atoms in one molecule of the compound. Therefore, the molecular formula will be (CClH2)2. To calculate the molar mass, we need to sum up the atomic masses of all the atoms in the molecular formula. Each element's atomic mass can be found on the periodic table. 🔍 Question 43: A compound has a simplest formula of NH3 with 3 nitrogen atoms per molecule. Determine its molar mass. 📝 Answer 43: Given: Simplest formula = NH3 with 3 nitrogen atoms per molecule To find the molecular formula, we write it as (NH3)3. To calculate the molar mass, we sum up the atomic masses of all the atoms in the molecular formula. Molar mass = (14 × 3) + (1 × 9) = 42 + 9 = 51 g/mol The molar mass of the compound is 51 g/mol. IF THE QUESTION REQUIRES FINDING THE MOLECULAR FORMULA WITH A DIFFERENT NUMBER OF CARBON ATOMS: Follow the same procedure by substituting the given simplest formula and the number of carbon atoms per molecule into the calculations. 🔍 Question 44: A compound has a simplest formula of C2H4O with 4 carbon atoms per molecule. What is its molar mass? 📝 Answer 44: Given: Simplest formula = C2H4O with 4 carbon atoms per molecule To find the molecular formula, we write it as (C2H4O)4. To calculate the molar mass, we sum up the atomic masses of all the atoms in the molecular formula. Molar mass = (12 × 2 × 4) + (1 × 4 × 4) + (16 × 4) = 96 + 16 + 64 = 176 g/mol The molar mass of the compound is 176 g/mol. Fantastic job! Determining the molecular formula and molar mass of a compound provides crucial information about its composition. Keep up the excellent progress! 🎉👍 Concept Explanation: To find the mass of a specific element in a compound, we need to consider the compound's molar mass and the mole ratio between the element and the compound. In this case, we are given the mass of ethanol, which is C2H5OH, and we need to determine the mass of carbon (C) in the compound. First, we calculate the number of moles of ethanol using the formula: n = m/M, where m is the given mass of ethanol and M is the molar mass of ethanol. Next, we determine the mole ratio of carbon in ethanol. Since there are 2 moles of carbon in 1 mole of ethanol, we multiply the number of moles of ethanol by the mole ratio to obtain the number of moles of carbon. Finally, we calculate the mass of carbon by multiplying the number of moles of carbon by the atomic mass of carbon. 🔍 Question 45: Find the mass of nitrogen present in 2.5 g of ammonium nitrate, NH4NO3. Given: mass of ammonium nitrate = 2.5 g R.T.F: mass of N = ? n = m/M = 2.5/80 = 0.03125 moles 1 mole of ammonium nitrate contains 1 mole of nitrogen n of N = 0.03125 moles m of N = n × M = 0.03125 × 14 = 0.4375 g 🔍 Question 46: Calculate the mass of oxygen present in 5.6 g of calcium carbonate, CaCO3. Given: mass of calcium carbonate = 5.6 g R.T.F: mass of O = ? n = m/M = 5.6/100 = 0.056 moles 1 mole of calcium carbonate contains 3 moles of oxygen n of O = 0.056 × 3 = 0.168 moles m of O = n × M = 0.168 × 16 = 2.688 g 🔍 Question 47: Determine the mass of hydrogen present in 1.8 g of water, H2O. Given: mass of water = 1.8 g R.T.F: mass of H = ? n = m/M = 1.8/18 = 0.1 moles 1 mole of water contains 2 moles of hydrogen n of H = 0.1 × 2 = 0.2 moles m of H = n × M = 0.2 × 1 = 0.2 g Concept Explanation: According to Avogadro's hypothesis, at the same temperature and pressure, equal volumes of different gases contain the same number of particles. Therefore, the ratio of the molecular masses of two gases can be determined by comparing the masses of equal volumes of the gases. In this case, we are given the masses of 1 dm3 of gas S and gas T, and we need to find the ratio of their molecular masses. To calculate the ratio, we divide the molecular mass of gas S by the mass of 1 dm3 of gas S, and then divide the molecular mass of gas T by the mass of 1 dm3 of gas T. 🔍 Question 48: At the same conditions of temperature and pressure, 1 dm3 of gas A has a mass of 2.0 g, while 1 dm3 of gas B has a mass of 3.5 g. Determine the ratio of the molecular masses of the two gases. Given: m of 1 dm3 of gas A = 2.0 g, m of 1 dm3 of gas B = 3.5 g R.T.F: Ratio of the molecular masses Molecular mass of gas A / mass of 1 dm3 of gas A = Molecular mass of gas B / mass of 1 dm3 of gas B Molecular mass of gas A = (2.0 g) x (Molecular mass of gas B) / (3.5 g) 🔍 Question 49: Under the same temperature and pressure, 1 dm3 of gas X has a mass of 1.8 g, while 1 dm3 of gas Y has a mass of 2.5 g. Find the ratio of the molecular masses of gas X and gas Y. Given: m of 1 dm3 of gas X = 1.8 g, m of 1 dm3 of gas Y = 2.5 g R.T.F: Ratio of the molecular masses Molecular mass of gas X / mass of 1 dm3 of gas X = Molecular mass of gas Y / mass of 1 dm3 of gas Y Molecular mass of gas X = (1.8 g) x (Molecular mass of gas Y) / (2.5 g) 🔍 Question 50: At the same temperature and pressure, 1 dm3 of gas P has a mass of 0.9 g, while 1 dm3 of gas Q has a mass of 1.2 g. Calculate the ratio of the molecular masses of gas P and gas Q. Given: m of 1 dm3 of gas P = 0.9 g, m of 1 dm3 of gas Q = 1.2 g R.T.F: Ratio of the molecular masses Molecular mass of gas P / mass of 1 dm3 of gas P = Molecular mass of gas Q / mass of 1 dm3 of gas Q Molecular mass of gas P = (0.9 g) x (Molecular mass of gas Q) / (1.2 g) Concept Explanation: When comparing the masses of different volumes of gases at the same temperature and pressure, we can determine the molar mass of one gas when the molecular formula and mass of another gas are given. This is based on the idea that equal volumes of gases at the same conditions contain an equal number of particles.In this case, we are given the mass of 5.0 dm3 of gas with the molecular formula C2H2 and the mass of 1.0 dm3 of gas D. We need to find the molar mass of gas D.To find the molar mass of gas D, we first calculate the mass of 5.0 dm3 of gas D by multiplying the mass of 1.0 dm3 by 5. Then, we can calculate the molar mass of gas D by setting up a ratio between the mass of 5.0 dm3 of gas D and the mass of 5.0 dm3 of C2H2.🔍 Question 51: At the same temperature and pressure, 2.0 dm3 of a gas with the molecular formula CO2 has a mass of 8.0 g, while 3.0 dm3 of gas E has a mass of 4.5 g. What is the molar mass of gas E?Given: mass of 2.0 dm3 of CO2 = 8.0 g, mass of 3.0 dm3 of gas E = 4.5 g R.T.F: Molar mass of gas E = ?Mass of 1 dm3 of gas E = 4.5 g Mass of 3 dm3 of gas E = 3 × 4.5 = 13.5 gMolar mass of gas E = (13.5 g) × (Molar mass of CO2) / (8.0 g)🔍 Question 52: Under the same temperature and pressure, 4.0 dm3 of a gas with the molecular formula H2 has a mass of 2.0 g, while 1.5 dm3 of gas F has a mass of 3.6 g. Determine the molar mass of gas F.Given: mass of 4.0 dm3 of H2 = 2.0 g, mass of 1.5 dm3 of gas F = 3.6 g R.T.F: Molar mass of gas F = ?Mass of 1 dm3 of gas F = 3.6 g Mass of 4 dm3 of gas F = 4 × 3.6 = 14.4 gMolar mass of gas F = (14.4 g) × (Molar mass of H2) / (2.0 g)🔍 Question 53: At the same temperature and pressure, 1.2 dm3 of a gas with the molecular formula CH4 has a mass of 3.0 g, while 2.5 dm3 of gas G has a mass of 4.0 g. Find the molar mass of gas G.Given: mass of 1.2 dm3 of CH4 = 3.0 g, mass of 2.5 dm3 of gas G = 4.0 g R.T.F: Molar mass of gas G = ?Mass of 1 dm3 of gas G = 4.0 g Mass of 2.5 dm3 of gas G = 2.5 × 4.0 = 10.0 gMolar mass of gas G = (10.0 g) × (Molar mass of CH4) / (3.0 g) Concept Explanation: When comparing the masses of gases at the same temperature and pressure, we can calculate the mass of one gas based on the mass of the same volume of another gas. This is possible because equal volumes of gases at the same conditions contain an equal number of particles. In this scenario, a flask containing gaseous C2H2 was weighed at a measured temperature and pressure, with a resulting mass of 1.50 g. The flask was then flushed and filled with nitrogen at the same temperature and pressure. We need to determine the mass of nitrogen in the flask. To find the mass of nitrogen, we use the principle that the masses of equal volumes of gases at the same conditions are proportional to their molar masses. We set up a ratio between the molar mass of nitrogen and the molar mass of C2H2, and then solve for the mass of nitrogen using the given mass of C2H2. 🔍 Question 54: A container holding gaseous H2 was weighed at a specific temperature and pressure, and its mass was found to be 2.50 g. The container was then purged and filled with oxygen at the same temperature and pressure. Calculate the mass of the oxygen in the container. Given: mass of H2 = 2.50 g R.T.F: mass of the same volume of oxygen? 🔍 Question 55: A vessel filled with gaseous CO2 was weighed under certain temperature and pressure conditions, yielding a mass of 3.75 g. The vessel was then emptied and filled with helium at the same temperature and pressure. Determine the mass of the helium in the vessel. Given: mass of CO2 = 3.75 g R.T.F: mass of the same volume of helium? 🔍 Question 56: A flask containing gaseous CH4 was weighed at a specific temperature and pressure, and its mass was determined to be 1.80 g. The flask was then evacuated and filled with argon at the same temperature and pressure. Find the mass of the argon in the flask. Given: mass of CH4 = 1.80 g R.T.F: mass of the same volume of argon? 📝 Answer 54: To calculate the mass of oxygen in the container, we can use the principle of proportional masses. Since the mass of H2 is 2.50 g, we can set up the following ratio: Molar mass of oxygen / Molar mass of H2 = Mass of oxygen / Mass of H2 From this ratio, we can solve for the mass of oxygen: Mass of oxygen = (Molar mass of oxygen / Molar mass of H2) * Mass of H2 📝 Answer 55: Similar to the previous question, we can set up a ratio between the molar mass of helium and the molar mass of CO2 to find the mass of helium in the vessel. 📝 Answer 56: Using the principle of proportional masses, we can calculate the mass of argon in the flask by setting up a ratio between the molar mass of argon and the molar mass of CH4.

f88b943c-f7c2-40a4-afeb-a70b512d0222 The reaction that takes place when a spark is introduced to a mixture of H2 and O2 gas Summary Exothermic