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Atoms Grade 10 SABIS SABIS The smallest unit of an element that retains the chemical properties of that element.

General physical properties of non-metals: brittle, do not have a luster do not conduct heat or electricity Grade 10 SABIS ​

Know the Potential Energy diagram for an Exothermic and Endothermic reactions Grade 10 SABIS ​ To understand how to determine the potential energy diagram for exothermic and endothermic reactions, let's first discuss what a potential energy diagram represents. A potential energy diagram is a graphical representation that shows the changes in potential energy of a chemical system as a reaction progresses. The vertical axis of the diagram represents the potential energy, while the horizontal axis represents the progress of the reaction from the initial state to the final state. Now, let's focus on exothermic reactions. An exothermic reaction is one that releases energy to the surroundings, usually in the form of heat. In an exothermic reaction, the products have lower potential energy than the reactants. This means that the potential energy decreases as the reaction proceeds. On a potential energy diagram for an exothermic reaction, the reactants are represented at a higher energy level compared to the products. The curve starts at a higher point (representing the energy of the reactants) and gradually decreases (representing the decrease in potential energy) as the reaction progresses towards the products. The difference in potential energy between the reactants and products is the amount of energy released to the surroundings. Now, let's move on to endothermic reactions. An endothermic reaction is one that absorbs energy from the surroundings. In an endothermic reaction, the products have higher potential energy than the reactants. This means that the potential energy increases as the reaction proceeds. On a potential energy diagram for an endothermic reaction, the reactants are represented at a lower energy level compared to the products. The curve starts at a lower point (representing the energy of the reactants) and gradually increases (representing the increase in potential energy) as the reaction progresses towards the products. The difference in potential energy between the reactants and products is the amount of energy absorbed from the surroundings. To determine the shape of the potential energy diagram, it is essential to consider the activation energy, which represents the energy barrier that must be overcome for the reaction to occur. The activation energy is depicted as the peak on the potential energy diagram. For an exothermic reaction, the activation energy is usually lower than the potential energy of the reactants, indicating that the reaction can readily occur. The potential energy decreases from the reactants to the products, with the activation energy acting as the barrier that needs to be overcome. In contrast, for an endothermic reaction, the activation energy is typically higher than the potential energy of the reactants. This indicates that more energy is required for the reaction to proceed. The potential energy increases from the reactants to the products, with the activation energy representing the energy threshold that must be surpassed. In summary, the potential energy diagram for exothermic reactions shows a gradual decrease in potential energy from the reactants to the products, while the diagram for endothermic reactions shows a gradual increase in potential energy. The activation energy represents the energy barrier that must be overcome. Understanding these diagrams helps visualize the energy changes and barriers involved in the progress of chemical reactions.

Dissolving salt into water to make a solution Grade 10 SABIS SABIS Physical

Recognize an endothermic/exothermic process, basing on knowledge and lab experience Grade 10 SABIS ​ Endothermic Processes: Melting ice or any solid substance. Evaporation of water or any liquid. Photosynthesis in plants, where sunlight is converted into chemical energy. Dissolving ammonium nitrate in water. Decomposition of limestone into lime and carbon dioxide upon heating. Electrolysis of water to produce hydrogen and oxygen gas. Absorption of heat by a cold pack to provide a cooling effect. Cooking food in an oven, where heat is absorbed by the food. The process of converting liquid water into steam. Dissolving barium hydroxide octahydrate in water. Exothermic Processes: Combustion of wood or any fuel, releasing heat and light. Formation of rust (oxidation of iron) with the release of heat. Neutralization of an acid with a base, such as hydrochloric acid and sodium hydroxide. Respiration in living organisms, where energy is released from glucose. Reaction between vinegar (acetic acid) and baking soda (sodium bicarbonate), resulting in the release of carbon dioxide gas. Reaction between sodium and chlorine to form sodium chloride, releasing heat and light. Freezing of water, where heat is released to the surroundings. Exothermic polymerization reactions, such as the curing of epoxy resin. Formation of precipitates during double displacement reactions, accompanied by the release of energy. Formation of bonds in exothermic chemical reactions, such as the reaction between hydrogen and oxygen to form water.

Coefficients Grade 10 SABIS SABIS The numbers placed before the reactants and products in a chemical equation, indicating how many molecules or atoms are involved.

Standard Temperature and Pressure (STP) Grade 10 SABIS SABIS 0⁰C and 1.00 atm pressure

Reaction of Alkali metals with oxygen. Grade 10 SABIS ​ Generally: 4M(s) + O2(g) → 2M2O(s) alkali metal + oxygen → alkali metal oxide

Convenient Reaction Ratio Grade 10 SABIS SABIS The ratio in which reactants combine or react to form products. It is often based on the coefficients in the balanced chemical equation and is used to simplify stoichiometric calculations.

< Back Electrochemistry ​ ​ Previous Next 🔬 Chapter 7: Redox Reactions 🔬 Learning Outcomes 🎯: Calculate oxidation numbers of elements in compounds and ions. Describe and explain redox processes in terms of electron transfer and changes in oxidation number. Use changes in oxidation numbers to help balance chemical equations. What is a Redox Reaction? 🔄: Oxidation is the gain of oxygen by an element or the loss of electrons. Reduction is the loss of oxygen or the gain of electrons. Redox reactions involve both oxidation and reduction processes. Oxidation and reduction always take place together in redox reactions. Redox reactions are crucial in various natural processes such as photosynthesis and respiration. Oxidation Numbers and Electron Transfer ⚖️: Oxidation numbers can be used to determine whether a substance has been oxidized or reduced during a chemical reaction. An increase in oxidation number indicates oxidation, while a decrease indicates reduction. Redox reactions can also be explained in terms of electron loss (oxidation) or electron gain (reduction). Balancing Redox Reactions 🧮: Half-equations can be used to represent the oxidation and reduction processes separately. Balancing redox reactions involves ensuring that the number of electrons lost in the oxidation process is equal to the number of electrons gained in the reduction process. Examples of Redox Reactions 🧪: The reaction between magnesium and oxygen to form magnesium oxide is an example of a redox reaction. The reaction between sodium and chlorine to form sodium chloride involves the transfer of electrons and is also a redox reaction. Rusting is an oxidation reaction that involves the reaction of iron with oxygen in the presence of water.

cm³ Grade 10 SABIS SABIS A unit of volume equal to one cubic centimeter, equivalent to 1 milliliter.

< Back Group 17 ​ ​ Previous Next 🔬 Chapter 11: Group 17 🔬 Halogens and Their Compounds 🧫: Halogens such as chlorine, bromine, and iodine exist as covalent diatomic molecules. They are oxidizing agents, with fluorine being the strongest and iodine the weakest. Chlorine reacts with cold hydroxide ions in a disproportionation reaction to produce commercial bleach. Chlorine has various industrial uses, including the manufacture of PVC and halogenated hydrocarbons used as solvents, refrigerants, and in aerosols. Chlorination of water with chlorine is important for the prevention of diseases.