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Chapter 5 SABIS Grade 10 Lesson 5

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Lesson 29


Part 5: A Closer Look at Effusion, Diffusion and Gas Behavior 👀💨🎈🌬

179. Effusion 💨:

Let's imagine you're inflating a balloon but it has a tiny hole. The gas escaping from this hole is an example of effusion. It's basically the passage of a gas through a small opening. If you've ever heard a balloon slowly hissing as it deflates, that's effusion at work! SQ36 🎈💨

180 - 182. Kinetic Energies and Gases ⚡🔥:

At the same temperature, the average kinetic energy (KE) of all ideal gases is the same. Crazy, right? This energy is directly proportional to the absolute temperature (KE = kT). Also, the KE is directly proportional to the gas's molar mass and inversely proportional to the gas velocity squared. Simply put, the lighter a particle is, the faster it moves (and the faster it effuses). 🏃‍♂️💨 SQ 37, 38

183 - 186. Speed of Gases and Kinetic Energy Comparisons 🏎💨:

When comparing the speed of different gases at the same temperature, we use this equation:

ν1/ν2 = √(M2/M1)

And when comparing the time required for two different gases to travel the same distance, we use this one:

t2/t1 = √(M2/M1)

Lastly, when comparing the kinetic energy of gases at different temperatures, we use:

KE1/KE2 = T1/T2

Don't worry, we'll go through examples of these. BQ17 🕓🔁

Exercise Time 🏋️‍♀️💡:

It's time to flex your brain muscles! Try to solve these exercises based on what you've learned so far. Once you're done, check your answers to see if you got them right. If not, don't worry - just go through the lesson again. Remember, practice makes perfect! 🏅📚

  1. 10 cm³ of Helium gas took 5.0s to effuse (diffuse from a small orifice) under certain conditions of temperature and pressure. Under the same conditions, it took another gas X 20.0s to effuse from the same orifice. Calculate the molar mass of gas X. Explain all your calculations. 📝🤔

  2. Which gas should diffuse faster, SO2 or CH4? How many times as fast? Why? 💨🔍

  3. The rate of diffusion of a particular gas was measured and found to be 24 cm³/min. Under the same conditions, the rate of diffusion of methane gas CH4 was found to be 47.8 cm³/min. What is the molar mass of the unknown gas? ⏱📊

  4. The molecules of an unknown gas, SOx, travel at 1⁄4 the speed (on average) of helium atoms at the same temperature. Calculate the molecular mass of SOx, and deduce the value of x. [O = 16; S = 32]. 🎈🔬

  5. Cooking gas is a mixture of two gases: propane (C3H8) and butane (C4H10). On average, the molecules of which gas have a higher kinetic energy? On average, the molecules of which gas are moving faster? How much faster? 🔥🍳

187. A Quantitative Investigation of the Reaction of Magnesium Metal with Hydrochloric Acid 🧪🧑‍🔬:

This part takes us back to chemistry class! Let's react magnesium (Mg) with hydrochloric acid (HCl). The reaction produces magnesium chloride (MgCl2) and hydrogen gas (H2). Here's what it looks like:

Mg (s) + 2 HCl (aq) → MgCl2 (aq) + H2 (g)

Observations during this reaction include the magnesium ribbon dissolving, effervescence due to the evolution of hydrogen gas, and the gas measuring cylinder tube becoming warm. When the H2 gas is produced, it's collected in a gas measuring tube. We have a set of instructions to properly read the volume of the gas and to determine its pressure.

188. Diffusion 🌬:

Now, let's not confuse effusion with diffusion! Diffusion is the term used to describe the mixing of gases. Imagine spraying perfume in one corner of your room. After a while, you start to smell it everywhere in the room. That's diffusion at work! It's the process of the spread of a gas throughout space. BQ16

Stay tuned for the next lesson where we'll put these principles to use with more real-world examples and exercises! 🌍🌟




Quiz Time: Test Your Gas Laws Knowledge! 📝🎯🎉

Let's see how well you've absorbed the knowledge! Answer these multiple-choice questions based on the lesson. You're doing a great job, and it's almost time to celebrate! 🎉💡

  1. What is Effusion? a) Mixing of gases b) Gas escaping through a small opening c) Gas transforming into a liquid d) Increase in pressure of a gas

  2. The average kinetic energy of an ideal gas is directly proportional to what? a) The gas's volume b) The absolute temperature c) The gas's pressure d) The gas's molar mass

  3. If two gases are at the same temperature, which gas's molecules will move faster? a) The one with the higher molar mass b) The one with the lower molar mass c) Both will move at the same speed d) There is not enough information to determine

  4. What is the difference between Effusion and Diffusion? a) Effusion is faster than Diffusion b) Diffusion is the process of gas escaping through a small opening while Effusion is the mixing of gases c) Effusion is the process of gas escaping through a small opening while Diffusion is the mixing of gases d) There is no difference, they are the same process

  5. In the reaction of magnesium with hydrochloric acid, what gas is produced? a) Oxygen b) Nitrogen c) Hydrogen d) Carbon Dioxide

Good luck! Remember to refer back to the lesson if you're unsure about any of the answers. And most importantly, have fun! 😃👍

💡 Pro Tip: Applying the 70% Rule - Remember, it's better to get 7 out of 10 questions right than to guess all of them without understanding. Always strive to truly understand at least 70% of the material. 🧠💪

Answers:

  1. b) Gas escaping through a small opening

  2. b) The absolute temperature

  3. b) The one with the lower molar mass

  4. c) Effusion is the process of gas escaping through a small opening while Diffusion is the mixing of gases

  5. c) Hydrogen

Keep learning and stay curious! The world of science is full of fascinating phenomena just waiting to be discovered. 🌟🔭📚👩‍🔬




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