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53e49697-409e-44ad-99bf-95f259a539b6 Health and safety issues related to Rate of reaction SABIS Summary Increasing the surface area of solid (by reduction of particle size) may cause explosion in some cases. For example  In flour mills, the air can fill with fine flour dust which has very large surface area. A spark can cause the flour to catch fire and explode.  In coal mines where the air is filled with very fine coal dust.

b8a83502-368f-4f79-9ba2-e31bd0809436 Observations for the reaction of alkali metal with water: Summary  Piece of metal floats (alkali metals have low density).  Piece of metal darts around.  A hissing sound is heard due to the evolution of a gas.  If red litmus paper is dipped in the solution, the paper turns blue due to the formation of the alkali metal hydroxide.  If few drops of phenolphthalein indicator are added to the water solution turns pink due to the formation of alkali metal hydroxide.  If the gas produced is tested with a lit splint, it burns with a squeaky pop sound.

3f8034d0-f7be-4de4-82e3-4ffef429ae45 cheat sheet ap chemistry unit 4 https://k-chemistry.my.canva.site/ap-chemistry-unit-4-cheat-sheet Summary

f55b1c1c-29e9-45a4-862f-2af67e06c626 Measurements and Calculations Calculations with Significant Figures Examples Summary

Problems on Chapter 4 Previous All Content Next 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.

Previous All Content Next Chapter 5 SABIS Grade 10 Lesson 2 Lesson 26 Chapter 5: Part 2 - Kinetic Theory of Gases Concept 1: The Basics of Kinetic Theory of Gases Temperature is a key player in how gas particles behave. Here's how it works: Average Kinetic Energy: The average kinetic energy of gas particles is directly related to the temperature. If you're at a party 🥳, think of the temperature as the volume of the music. The louder (hotter) the music, the more energy you have to dance 💃! As the temperature increases, particles move more rapidly. They also collide with the walls of the container more frequently and with more force. This leads to an increase in the pressure of the gas. It's like when you're making popcorn 🍿! The more heat, the faster the kernels pop and hit the inside of the popcorn maker, and the more popcorn you have in the end! Quick Understanding Check: If you have a gas inside a container and you increase the temperature, what happens to the gas particles? Answer: If the temperature increases, the gas particles move more rapidly and collide more frequently and strongly with the walls of the container. Test your understanding: What happens to the average kinetic energy of a gas when the temperature increases? A) It decreases B) It stays the same C) It increases D) It disappears What happens to the gas particles when the temperature increases? A) They move more slowly B) They collide less frequently with the container walls C) They move more rapidly and collide more frequently and strongly with the container walls D) They stop moving If you increase the temperature of a gas, what happens to the pressure it exerts on its container? A) It decreases B) It stays the same C) It increases D) It becomes zero If you compare a gas at a low temperature with a gas at a high temperature, which one has particles that move more rapidly? A) The gas at low temperature B) The gas at high temperature C) Both move at the same rate D) It depends on the type of gas If you decrease the temperature of a gas, what happens to the pressure it exerts on its container? A) It increases B) It stays the same C) It decreases D) It becomes zero Concept 2: Kinetic Energy and Temperature in Gases Now that we understand the basic idea of gas particle movement and pressure, let's look at how kinetic energy and temperature come into play. Kinetic Energy: The average kinetic energy of a gas - that's the energy it has due to its motion - is constant at a constant temperature. Just like when you keep pedaling a bike at a steady pace, your kinetic energy stays the same. Temperature and Energy: As temperature increases, the average kinetic energy of a gas increases. This is similar to how your body heats up when you exercise - as you work harder (increase your energy), your body temperature rises. Temperature and Pressure: As temperature increases, particles move more rapidly. They collide with the wall of the container more frequently and more strongly, so the pressure of the gas increases. This is like increasing the speed of a pinball machine. The ball (or particles) starts moving faster and hits the sides more often, which increases the pressure. 🏓💥 Concept 3: Ideal and Real Gases Gases can be categorized into two types: ideal and real. But what do these terms mean? Ideal Gas: An ideal gas always stays as a gas even when cooled. It perfectly follows the law PV = constant, where P is pressure and V is volume. It's called "ideal" because it's a model we use for calculations, but no real gas behaves ideally under all conditions. Imagine a unicorn - we have an idea of what it is, but it doesn't exist in real life. 🦄 Real Gas: Real gases can liquefy upon cooling. They follow the law PV = constant only approximately. They behave like ideal gases at high temperatures and low pressures. But as pressure increases and volume decreases, real gases can liquefy, and the PV = constant rule no longer applies. Imagine water vapor condensing into water; it goes from a gas to a liquid under certain conditions. 💨➡️💧 Quick Understanding Check: Why is an ideal gas called "ideal"? Answer: An ideal gas is called "ideal because it perfectly follows the law PV = constant and it doesn't change state upon cooling. It is a model used for calculations, but no real gas behaves ideally under all conditions.Test your understanding:What happens to an ideal gas when it is cooled? ❄️A) It liquefiesB) It remains a gasC) It becomes a solidD) It evaporates Answer: B) It remains a gas How does a real gas behave under high temperatures and low pressures? 🌡️⬆️ & ⬇️A) Like a liquidB) Like a solidC) Like an ideal gasD) It disappears Answer: C) Like an ideal gas Why doesn't PV = constant apply to real gases under all conditions? ❓A) Because they can liquefy under certain conditionsB) Because they always stay as gasesC) Because they can solidifyD) Because they can evaporate Answer: A) Because they can liquefy under certain conditions If we recall the earlier concept, increasing temperature causes gas particles to move more rapidly, colliding more frequently and strongly with the container, thus increasing pressure. Now, consider a real gas under these conditions. As the pressure increases and volume decreases, what happens to the real gas? 🌡️⬆️➡️💥⬆️➡️❓A) It becomes an ideal gasB) It stays the sameC) It liquefiesD) It evaporates Answer: C) It liquefies Compare an ideal gas and a real gas. Which one perfectly follows the law PV = constant? 🅿️✖️🅱️=⏹️A) Ideal gasB) Real gasC) BothD) Neither Answer: A) Ideal gas Concept 4: Temperature, Volume, and Molar Mass Temperature not only affects the pressure and kinetic energy of a gas, but also its volume. Also, the molar mass of a gas affects its freezing point (FP) and boiling point (BP). Temperature and Volume: As the temperature of a fixed mass of gas at constant pressure increases, so does its volume. It's like blowing up a balloon - as you add more air (increase the temperature), the balloon (volume) gets bigger. 🎈⬆️ Temperature Units: T(K) = t(°C) + 273. This is how you convert temperature from Celsius to Kelvin. Kelvin is a temperature scale used in physical sciences. The Kelvin has the same magnitude as the degree Celsius, but it starts at absolute zero - the lowest temperature possible in the universe! 🌡️🔄 Molar Mass and FP/BP: The higher the molar mass, the higher the freezing point (FP) and boiling point (BP). It's like being heavier makes it harder for you to get moving (higher FP) and harder for you to stop once you're going (higher BP). ⚖️➡️❄️/🌡️ Quick Understanding Check: If the temperature of a gas increases, what happens to its volume (assuming the gas is at constant pressure)?Answer: If the temperature of a gas increases, its volume also increases.Test your understanding:What happens to the volume of a fixed mass of gas at constant pressure if its temperature increases? 🌡️⬆️➡️🅱️❓A) It decreasesB) It remains the sameC) It increasesD) It disappears Answer: C) It increases How do you convert temperature from degrees Celsius to Kelvin? 🌡️🔄A) T(K) = t(°C) + 273B) T(K) = t(°C) - 273C) T(K) = t(°C) * 273D) T(K) = t(°C) / 273 Answer: A) T(K) = t(°C) + 273 What does a higher molar mass mean for a gas's freezing and boiling points? ⚖️➡️❄️/🌡️A) Lower freezing and boiling pointsB) Higher freezing and boiling pointsC) Unchanged freezing and boiling pointsD) No freezing or boiling points Answer: B) Higher freezing and boiling points From our previous concepts, we know that increasing temperature causes an increase in both kinetic energy and pressure in gases. Now, if you increase the temperature of a fixed mass of gas at constant pressure, what happens to its volume? 🌡️⬆️➡️🅱️❓A) It decreasesB) It stays the sameC) It increasesD) It becomes zero Answer: C) It increases Considering all the concepts we've learned so far, if a real gas is at high temperatures and low pressures, and its volume is decreasing while its temperature is increasing, what would likely happen to this gas? 🌡️⬆️🅿️⬇️🅱️⬇️➡️❓A) It would behave like an ideal gasB) It would liquefyC) Its pressure would decreaseD) Its volume would increase Answer: B) It would liquefy Final Quiz - Chapter 5: Lesson 2 📝 (2 marks) Gas particles move in ________ directions. A) Straight B) Circular C) Random D) Back and forth (2 marks) If you increase the temperature of a gas, its pressure __________. A) Decreases B) Stays the same C) Increases D) Becomes zero (2 marks) An ideal gas follows the law __________ perfectly. A) PV = variable B) PV ≠ constant C) PV = constant D) PV = 0 (2 marks) Real gases behave like ideal gases under __________. A) High temperatures and high pressures B) Low temperatures and low pressures C) High temperatures and low pressures D) Low temperatures and high pressures Answer: C) High temperatures and low pressures (2 marks) If the temperature of a fixed mass of gas at constant pressure increases, its volume __________. A) Decreases B) Stays the same C) Increases D) Becomes zero Answer: C) Increases (2 marks) The higher the molar mass of a gas, the ________ its freezing point (FP) and boiling point (BP). A) Lower B) Higher C) Unchanged D) None of the above Answer: B) Higher (3 marks) If a real gas is under high temperatures and low pressures, and you increase its temperature while decreasing its volume, the gas is likely to ________. A) Behave like an ideal gas B) Liquefy C) Have its pressure decrease D) Increase in volume Answer: B) Liquefy (3 marks) The kinetic theory of gases assumes that gas particles move ________. A) Only when heated B) In a straight line always C) At random D) In a circular pattern Answer: C) At random (3 marks) The volume of an ideal gas is directly proportional to the __________. A) Pressure B) Absolute temperature C) Mass D) Molar mass Answer: B) Absolute temperature (3 marks) The average kinetic energy of a gas is constant at ________. A) Constant pressure B) Constant volume C) Constant temperature D) None of the above Answer: C) Constant temperature Total Marks: 24 Passing Score: 17 (Approximately 70%) To calculate your percentage, divide your score by the total marks and multiply by 100. For example, if your score is 20, your percentage would be (20/24)*100 = 83.33%. That's all for today's lesson! Keep practicing, and always be curious! 🎓🔬🚀 Go to Lesson 3

5c0eaceb-a1c5-4a58-8ba5-d19141e50b5c < Back Previous Next 💎🔬 Purification 🔬💎 Purification involves using electrolysis to remove impurities from a metal. For instance, in the purification of copper: The cathode (-ve electrode) is pure copper. The anode (+ve electrode) is impure copper. The electrolyte is aqueous copper (II) sulfate. During electrolysis, copper ions (Cu2+) in the electrolyte are reduced (gain electrons) at the cathode and become solid copper atoms. Meanwhile, solid copper atoms at the anode are oxidized (lose electrons) and become copper ions (Cu2+), entering the electrolyte. This maintains the electrolyte's concentration, as the ions being deposited on the cathode are replaced by the ions from the anode. Any impurities in the anode copper do not dissolve and fall to the bottom. ⚗️🧪 Electroplating 🧪⚗️ Electroplating is a process that uses electrolysis to coat a metal object with a thin layer of another metal. The primary purposes of electroplating are to enhance the object's appearance and to protect it from corrosion. In a typical electroplating process: The cathode (-ve electrode) is the object to be electroplated. The anode (+ve electrode) is the metal used for coating (for example, silver). The electrolyte is a solution containing ions of the metal used for coating (for example, silver nitrate). As electrolysis proceeds, metal ions from the electrolyte are reduced at the cathode and become solid metal atoms, adhering to the object's surface. Meanwhile, at the anode, the metal is oxidized and releases ions into the electrolyte, maintaining its concentration. It's crucial to ensure the object to be electroplated is clean and entirely immersed in the electrolyte. Also, rotating it can help achieve an even coating. Regarding your reference to a past paper question (Specimen 2023, 2, q30), could you provide more context or the actual question? Unfortunately, I can't access specific past papers beyond my knowledge cut-off in September 2021. However, I'd be more than happy to help if you could provide more details about the question! Press Next for the next lesson Electricity Lesson 3 Next Topic

684fb4ba-d7b8-4380-962d-b63edd43ceb5 Cooking a steak until it is well done Summary Chemical