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731c63f0-388c-4ddc-a8bc-30a23a39d0b8 Application on Hess’s Law medium Grade 10 SABIS Question 1: Given the following reactions and their respective enthalpy changes: C(s) + O2(g) → CO2(g) ΔH1 = -393.5 kJ/mol H2(g) + 1/2O2(g) → H2O(l) ΔH2 = -286.0 kJ/mol C(s) + H2(g) → CH4(g) ΔH3 = -74.8 kJ/mol Calculate the enthalpy change for the reaction: CH4(g) + 2O2(g) → CO2(g) + 2H2O(l) Answer 1: To calculate the enthalpy change for the given reaction, we can use Hess's Law. By manipulating the given reactions, we can cancel out the common compounds and add the enthalpy changes. Multiplying reaction 1 by 2 gives: 2C(s) + 2O2(g) → 2CO2(g) 2ΔH1 = 2(-393.5 kJ/mol) = -787.0 kJ/mol Multiplying reaction 2 by 2 gives: 2H2(g) + O2(g) → 2H2O(l) 2ΔH2 = 2(-286.0 kJ/mol) = -572.0 kJ/mol Adding reactions 3, 2, and 1 gives: C(s) + H2(g) + 2H2(g) + O2(g) + 2O2(g) → CH4(g) + 2H2O(l) + 2CO2(g) ΔH3 + 2ΔH2 + 2ΔH1 = -74.8 kJ/mol + (-572.0 kJ/mol) + (-787.0 kJ/mol) = -1433.8 kJ/mol Since the given reaction is the reverse of the calculated reaction, the enthalpy change for the given reaction is the negative of the calculated value. ΔH = -(-1433.8 kJ/mol) = 1433.8 kJ/mol Question 2: Given the following reactions and their respective enthalpy changes: 2SO2(g) + O2(g) → 2SO3(g) ΔH1 = -198.2 kJ/mol S(s) + O2(g) → SO2(g) ΔH2 = -296.8 kJ/mol 2S(s) + 3O2(g) → 2SO3(g) ΔH3 = -792.0 kJ/mol Calculate the enthalpy change for the reaction: 2SO2(g) + O2(g) → 2SO3(g) + 198.2 kJ Answer 2: To calculate the enthalpy change for the given reaction, we can use Hess's Law. By manipulating the given reactions, we can cancel out the common compounds and add the enthalpy changes. Multiplying reaction 2 by 2 gives: 2S(s) + 2O2(g) → 2SO2(g) 2ΔH2 = 2(-296.8 kJ/mol) = -593.6 kJ/mol Adding reactions 1 and 2 gives: 2SO2(g) + O2(g) + 2S(s) + 2O2(g) → 2SO3(g) + 2

d377aebc-40c6-4007-aa48-8c2f6c5c5cc4 The burning of a magnesium ribbon in air Grade 10 SABIS SABIS Exothermic

56daf7db-50c2-4b6a-9429-151f75319d8d The boiling and melting points of alkali metals decreases as their atomic # increases. Grade 10 SABIS

Previous All Content Next Chapter 2 Questions and Problems 📝 Lesson 9📝 Chapter 2 Problems and Questions 1️⃣🍀 Easy Questions 🌡 What is the change of a substance from solid to liquid at a definite temperature called? 🌬 Define evaporation in your own words. 🌞 What does the horizontal part of the heating curve represent? ❄️ What does the phase change in the cooling curve signify? 🌡 How does the position of the horizontal part on the heating curve relate to the melting point of the solid? ❄️ What is the physical constant for the temperature at which a solid changes to a liquid at the same temperature and pressure? 🔵 Intermediate Questions 📉 Given a cooling curve of a pure compound, explain the stages in detail. 🎈 Assume the initial volume of a gas is 3L and its pressure is 4 atm. If the pressure is reduced to 2 atm, what will be the new volume, according to Boyle's law? 🎈 What happens to the volume of a gas if the pressure is doubled while the temperature is held constant, according to Boyle's law? ⏳ You have a pure compound, the larger is the amount of solid heated, what happens to the time it needs for the sample to start melting and to melt completely? 📝 Answer : The larger is the amount of solid heated the longer is the time it needs for the sample to start melting and to melt completely. 🌡️ How does the temperature affect the average kinetic energy of the particles during the phase change in the heating curve of a pure compound? 📝 Answer : During the phase change, the temperature remains constant. So, the average kinetic energy of the particles does not change. The added energy is used to change the phase of the substance. 🔴 Difficult Questions 📈 Given a heating curve with the first stage having a slope of 3 and the third stage having a slope of 5, can you justify why the slopes are different? 🎈 If a sample of gas has an initial volume of 100 mL at a pressure of 500 kPa and the pressure is increased to 1000 kPa, what would the final volume of the gas be according to Boyle's law? 🧊 Given a cooling curve of a pure compound, explain the changes in kinetic and potential energy during the phase transitions. 🌡️ How does the phase change represented in the cooling curve differ from the phase change represented in the heating curve? 💠 Advanced Questions 🌡️ Based on a heating curve, describe the kinetic and potential energy changes during each phase transition. 🎈 If the pressure of a gas sample is halved, what will happen to the volume according to Boyle's law? 📈 Draw and explain the stages of a heating curve of a pure compound. 🎈 If a gas has an initial volume of 5L at a pressure of 2 atm and the pressure is increased to 4 atm, what will be the final volume according to Boyle's law? 🌡️ What is the definition of a phase in the context of states of matter? 🏆 Champion-Level Questions 📈 Explain why the heating curve has a flat horizontal part where the solid changes to a liquid and the graph remains horizontal until all the solid melts. 🎈 If a gas initially at 20L and 5 atm is compressed to a volume of 10L, what will the final pressure be according to Boyle's law? 📉 Based on a cooling curve, how does the size of the liquid cooled affect the time it needs to start freezing and to freeze completely? 📈 Given a heating curve, how does the energy added during the phase change from solid to liquid relate to the potential energy of the particles? 🎈 If a sample of gas has a volume of 200 mL at 3 atm, and the pressure is increased to 6 atm, what would be the new volume according to Boyle's law? 🌡️ Describe what happens during the second stage of the heating curve of a pure compound. 🎈 According to Boyle's law, if a gas sample at 300 K with a volume of 2L experiences a pressure increase from 2 atm to 5 atm, what is the new volume? 📈 What determines the melting point of a solid based on the heating curve? 🌡️ Based on a cooling curve, how does the amount of liquid cooled affect the time it takes for the sample to freeze completely? 🎈 According to Boyle's law, if a gas sample at 1 atm and 5L is compressed to a volume of 2L, what will be the new pressure? 🌡️ In a cooling curve of a pure compound, which phase exists in the first stage and which phase in the third stage?📝 Answer : In a cooling curve of a pure compound, the compound exists as a liquid in the first stage and as a solid in the third stage.🎈 According to Boyle's law, what happens to the volume of a gas if the pressure is halved, while the temperature is held constant?📝 Answer : According to Boyle's law, if the pressure is halved, the volume of the gas will double.📈 Given a heating curve of a pure compound, explain why the slopes of the first and third stages are different.📝 Answer : The slopes are different because they represent different heat capacities of the solid and liquid phases of the substance. The steeper slope in the third stage indicates that more energy is needed to raise the temperature of the liquid compared to the solid.🌡️ What physical property determines the position of the horizontal part in a heating curve of a solid compound?📝 Answer : The position of the horizontal part in a heating curve of a solid compound is determined by the melting point of the solid.🎈 A gas has a volume of 10L at a pressure of 3 atm. If the volume is reduced to 5L, what will be the new pressure, according to Boyle's law?📝 Answer : According to Boyle's law, P1V1 = P2V2. So, the new pressure would be (3 atm * 10L) / 5L = 6 atm.🌡️ How does the size of the solid heated affect the time it takes for the sample to start melting and to melt completely, according to the heating curve?📝 Answer : The larger the amount of solid heated, the longer it takes for the sample to start melting and to melt completely.🎈 According to Boyle's law, what will happen to the volume of a gas if the pressure is doubled, while the temperature is held constant?📝 Answer : According to Boyle's law, if the pressure is doubled, the volume of the gas will be halved.📈 Explain the second stage of a cooling curve of a pure compound.📝 Answer : The second stage of a cooling curve represents the phase transition from liquid to solid (freezing). During this stage, the temperature remains constant as the liquid changes to solid.🌡️ What is the melting point of a substance?📝 Answer : The melting point is the temperature at which a solid changes to a liquid at the same temperature and pressure.🎈 If a gas sample has an initial volume of 2L at a pressure of 1 atm and the pressure is increased to 3 atm, what will be the new volume, according to Boyle's law?📝 Answer : According to Boyle's law, P1V1 = P2V2. So, the new volume would be (1 atm * 2L) / 3 atm = 0.67L.🌡️ In the first and third stages of a heating curve, there is a change in temperature, what does this indicate about the average kinetic energy of the particles?📝 Answer : In the first and third stages of a heating curve, there is a change in temperature, which means the average kinetic energy of the particles is increasing.🎈 Boyle's law states that for a given sample of gas (fixed amount) the volume of the gas varies inversely with the pressure at constant temperature. Express this mathematically.📝 Answer : Mathematically, Boyle's law can be expressed as P1V1 = P2V2, where P1 and V1 are the initial pressure and volume, and P2 and V2 are the final pressure and volume.📈 What does the second stage of the heating curve represent when a pure compound changes from solid to liquid?📝 Answer : The second stage of the heating curve represents the phase transition from solid to liquid, often called melting or fusion.🌡️ Explain the significance of the horizontal part of a cooling curve.📝 Answer : The horizontal part of a cooling curve represents the phase transition from liquid to solid (freezing). The temperature remains constant during this phase transition because the heat removed is used to change the phase, not to lower the temperature.🎈 Given a sample of gas with an initial volume of 1L at a pressure of 2 atm, if the volume is reduced to 0.5L, what will be the new pressure according to Boyle's law?📝 Answer : According to Boyle's law, P1V1 = P2V2. So, the new pressure would be (2 atm * 1L) / 0.5L = 4 atm.🌡️ How does the second stage of a heating curve, the plateau, reflect on the average kinetic energy and potential energy of the particles?📝 Answer : In the second stage, the plateau, the average kinetic energy of the particles is constant (hence, the temperature is constant), while the potential energy increases as the heat is used to break intermolecular bonds and change the phase from solid to liquid.🎈 If a gas sample with a volume of 300 mL at a pressure of 5 atm is allowed to expand to a volume of 600 mL, what would be the new pressure according to Boyle's law?📝 Answer : According to Boyle's law, P1V1 = P2V2. So, the new pressure would be (5 atm * 300 mL) / 600 mL = 2.5 atm.📈 Explain how the amount of solid heated affects the time it takes for the sample to start melting and to melt completely based on a heating curve.📝 Answer : The larger the amount of solid heated, the longer it takes for the sample to start melting and to melt completely, because more heat is needed to overcome the intermolecular forces in a larger amount of substance.🌡️ Explain what happens during the first and third stages of a cooling curve.📝 Answer : In the first stage of a cooling curve, the liquid is cooling and the temperature decreases until it reaches the freezing point. In the third stage, the liquid has completely turned into a solid and continues to cool down, with the temperature continuing to decrease.🎈 If a sample of gas has an initial volume of 400 mL at a pressure of 2 atm and the pressure is increased to 4 atm, what would be the new volume according to Boyle's law?📝 Answer : According to Boyle's law, P1V1 = P2V2. So, the new volume would be (2 atm * 400 mL) / 4 atm = 200 mL.

684fb4ba-d7b8-4380-962d-b63edd43ceb5 Cooking a steak until it is well done Grade 10 SABIS SABIS Chemical

69361492-6bf2-47c0-ac8c-dc6a48a52458 Heating water from 20°C to 80°C Grade 10 SABIS SABIS Endothermic

Previous All Content Next Chapter 5 SABIS Grade 10 Lesson 3 Lesson 27 Part 3: Measuring Gas Pressure using Manometers 📏🧪 Understanding how to measure the pressure of a gas is super important! For this, we use an instrument called a manometer. Let's look into two types: the closed-end manometer and the open-end manometer. Atmosphere 🌍: Before we dive in, remember that an atmosphere is the pressure that can support a column of mercury 760 mm high at 0°C. It's kind of like the weight a really tall person (about the height of a giraffe 🦒!) would exert if they were standing on your shoulders! Closed-End Manometer 🚰: This type of manometer measures the pressure of a gas directly. It's kind of like weighing yourself on a scale 🛀 - the number you see is directly related to your weight! If the gas container is empty (like a vacuum), both sides of the manometer have the same level of mercury. Picture a see-saw ⚖️ with nobody on it - it's perfectly balanced! The difference in height of mercury between the two arms of the manometer is independent of the atmospheric pressure. It's like listening to your favorite song 🎧 with noise-canceling headphones - you don't care about the noise around you! Open-End Manometer 🛁: This manometer measures the difference between the pressure of a gas in a container and the atmosphere. It's kind of like when you are in a hot air balloon 🎈 and you measure your height not from the ground, but from the cloud ☁️ next to you! The pressure of the gas is measured by the difference in height of mercury between the two arms of the manometer. Quick Understanding Check: If you are using a closed-end manometer and the container is empty, what would be the difference in the mercury level on both sides? Answer: The level of mercury on both sides would be the same. Test Your Understanding: What instrument is used to measure gas pressure? A) Barometer B) Thermometer C) Manometer D) Hydrometer Answer: C) Manometer If a closed-end manometer is attached to an empty container, what happens to the mercury level? A) The level is higher on one side B) The level is lower on one side C) The levels on both sides are equal D) There is no mercury Answer: C) The levels on both sides are equal An open-end manometer measures: A) Only atmospheric pressure B) Only the gas pressure in a container C) The difference between the gas pressure and atmospheric pressure D) The difference between the gas pressure and the vacuum pressure Answer: C) The difference between the gas pressure and atmospheric pressure A closed-end manometer's measurement is affected by atmospheric pressure. A) True B) False Answer: B) False What supports a column of mercury 760 mm high at 0°C? A) A vacuum B) Atmospheric pressure C) The pressure in a container D) Manometer pressure Answer: B) Atmospheric pressure Coming up next, our final quiz to see how well you've understood all of the concepts in this lesson! Don't worry, you got this! 🧠💪🚀 Alright! It's quiz time! Let's see how well you've understood the kinetic theory of gases. 📚✨💡 Final Quiz: What are the tiny particles in a gas always doing? A) Standing still B) Moving in a straight line C) Moving at random D) Following a set pattern If you have a gas inside a container and you increase the temperature, what happens to the gas particles? 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 What instrument is used to measure gas pressure? A) Barometer B) Thermometer C) Manometer D) Hydrometer If a closed-end manometer is attached to an empty container, what happens to the mercury level? A) The level is higher on one side B) The level is lower on one side C) The levels on both sides are equal D) There is no mercury The pressure exerted by gas particles is similar to: A) A gentle breeze B) A punch from a tiny fist C) A tickle from a feather D) The pull of gravity 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 An open-end manometer measures: A) Only atmospheric pressure B) Only the gas pressure in a container C) The difference between the gas pressure and atmospheric pressure D) The difference between the gas pressure and the vacuum pressure A closed-end manometer's measurement is affected by atmospheric pressure. A) True B) False What supports a column of mercury 760 mm high at 0°C? A) A vacuum B) Atmospheric pressure C) The pressure in a container D) Manometer pressure 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. This situation can be compared to: A) A calm day at the beach 🏖️ B) A slow walk in the park 🚶♂️ C) A wild party with loud music 🥳🎶 D) A quiet night reading a book 📖 Remember, each question is worth 10 points, making the total quiz out of 100 points. If you scored 70 points or more, great job! You've passed! If not, take another Quiz Answer Key: C) Moving at random C) They move more rapidly and collide more frequently and strongly with the container walls C) Manometer C) The levels on both sides are equal B) A punch from a tiny fist C) It increases C) The difference between the gas pressure and atmospheric pressure B) False B) Atmospheric pressure C) A wild party with loud music 🥳🎶 Go to Lesson 4 ____________________________________________

4a86fc54-4e19-4320-82f5-aec48e238da7 Heating Curve A graphical representation of the relationship between temperature and time as a substance is heated.

655e701e-b6cf-4f0a-9de7-38636ef4de98 Melting Point/Freezing Point ! Widget Didn’t Load Check your internet and refresh this page. If that doesn’t work, contact us. ! Widget Didn’t Load Check your internet and refresh this page. If that doesn’t work, contact us.

Lesson 34 Previous All Content Next Chapter 6 SABIS Grade 10 Part 4 Lesson 34 261. Demonstration: Sublimation: Examples of solids that can sublime at room temperature: 1) Solid iodine, I2 (s) 2) Dry ice or solid carbon dioxide CO2 (s) 3) Any ammonium compound as ammonium chloride, NH4Cl and ammonium bromide, NH4Br 262. Demonstration: Simple Distillation 263. Demonstration: Fractional distillation. Discuss briefly: fractional distillation of liquefied air and fractional distillation of crude oil. 264. Demonstration: Separating funnel 265. Adsorption: means sticking to the surface. 266. Adsorption: sticking of the particles of one material on the surface of another. Examples of adsorbing substances: Silica gel: adsorbs water vapor, Charcoal: adsorbs gases with strong odor and removes colored impurities from a solution 267. Demonstration: Chromatography. It is the technique used to separate different compounds, especially those that can be easily destroyed by heat or chemicals. It can be used to separate colored components as: 1) Green liquid obtained by squashing green leaves. 2) Black ink. The property that carries the liquid up the paper is capillary action. 268. Demonstration: Crystallization 269. Alcohol is flammable, therefore it cannot be heated directly. To heat alcohol, we should use a steam bath or an electric heater. 270. If you need to collect sugar from sugar alcohol solution heat the solution using an electric heater to crystallization point. Leave the solution to cool and crystals to form. Filter off the crystals. 271. Vapor pressure and temperature are proportional NOT directly proportional. At the same temperature, the vapor pressure is the SAME. For the same liquid, the only factor affecting the pressure of the liquid is the temperature. 272. Minimum conditions for liquid molecules to vaporize: 1) Molecules are supposed to be on the surface. 2) Molecules are supposed to have an average kinetic energy greater than the energy keeping the molecules in the liquid state. 273. Water has a vapor pressure of 17.5 mmHg at 20oC. Which of the following will increase the vapor pressure of water? a) Transferring water to a larger container. b) Cooling water to 10oC c) Taking the container to the top of the mountain. d) Heating the water to 32oC 274. Boiling point: is the temperature at which the liquid vaporizes anywhere in the solution. 275. At the boiling point: a. Vapor pressure is equal to the surrounding pressure. b. Bubbles of vapor can form anywhere within the liquid. c. Molecules escape from the surface of the liquid to enter the gas phase as vapor (this also happens at room temperature). d. With increasing altitude, atmospheric pressure decreases and so does boiling point. 276. Normal boiling point: is the temperature at which the vapor pressure is exactly 1 atm or 760 mmHg. 277. Molar heat of fusion: is the energy required to change one mole of a substance from solid to liquid at the same temperature and constant pressure. 278. General equation for Molar heat of vaporization: X (l) + heat ⇌ X (g) 279. General equation for Molar heat of condensation: X (g) ⇌ X (l) + heat 280. In general, a substance that has a higher boiling point is expected to have a 281. An aqueous solution is one in which the solvent is water. 282. Salt and water is an example of aqueous solutions where the solute is a solid. 283. Alcohol and water is an example of aqueous solutions where the solute is a liquid. 284. Ammonia and water is an example of aqueous solutions where the solute is a gas. 285. Concentration: relative amounts of solute and solvent. 286. Molar concentration (Molarity): is the number of moles of solute per liter (dm3) of solution. (the relative amounts of solute and solution) 287. Concentration of a given solution does not change if solution is split into fractions. 288. Relationships between n, V, C and m, M, V, C: n = CV, 𝐂 = 𝐦/𝐕, 𝐕 = 𝐦/𝐂, m = n × M, m = CVM, 𝐌 = 𝐦/𝐂𝐕 289. Preparing solutions with given concentrations. 290. A 2 L bottle of 0.35 M solution is split into ten containers of 100ml capacity. What is the concentration of the solution in each of the new containers? a) 0.75 M b) 0.0035 M c) 2.0 M d) 0.35 M e) 100 M 291. Demonstration: Sublimation: Examples of solids that can sublime at room temperature: 1) Solid iodine, I2 (s) 2) Dry ice or solid carbon dioxide CO2 (s) 3) Any ammonium compound as ammonium chloride, NH4Cl and ammonium bromide, NH4Br 292. Demonstration: Simple Distillation 293. Demonstration: Fractional distillation. Discuss briefly: fractional distillation of liquefied air and fractional distillation of crude oil. 294. Demonstration: Separating funnel 295. Adsorption: means sticking to the surface. 296. Adsorption: sticking of the particles of one material on the surface of another. Examples of adsorbing substances: Silica gel: adsorbs water vapor, Charcoal: adsorbs gases with strong odor and removes colored impurities from a solution 297. Demonstration: Chromatography. It is the technique used to separate different compounds, especially those that can be easily destroyed by heat or chemicals. It can be used to separate colored components as: 1) Green liquid obtained by squashing green leaves. 2) Black ink. The property that carries the liquid up the paper is capillary action. 298. Demonstration: Crystallization 299. Alcohol is flammable, therefore it cannot be heated directly. To heat alcohol, we should use a steam bath or an electric heater. 300. If you need to collect sugar from sugar alcohol solution heat the solution using an electric heater to crystallization point. Leave the solution to cool and crystals to form. Filter off the crystals.

e5bb001d-74b3-47c2-bb84-061688fe1d75 < Back Previous Next The Periodic table Next Topic

dab7e121-962d-4f46-b93f-1132d9f493fd Chapter 7 PDF Grade 10 SABIS Elements Monoatomic Gaseous Elements Diatomic Gaseous Elements Liquid Elements Inert Elements Halogens Alkali Metals Transition Metals Properties of Elements Physical Properties Metals Non-Metals Specific Properties Graphite Iodine Potassium Properties of Group I Elements Physical Properties Chemical Properties Periodic Table Structure Rows and Columns Position of Metals and Non-Metals Chemical Reactions Alkali Metals with Various Elements Halogens with Various Elements Displacement Reactions Compounds Types of Compounds Ionic Compounds Molecular Compounds Isoelectronic Species Specific Compounds Alkali Metal Hydrides Alkali Metal Halides Hydrogen Halides Chemical Tests Flame Test for Alkali Metals Identification of Halide Ions Identification of Unknown Alkali Halide Chemistry of Third-Row Elements Hydrides Chlorides Oxides Chemical Reactivity in the Periodic Table Reactivity of Various Groups Additional Exercises and Notes 1819 Level L Chemistry Chapter 7 Notes (2) .pdf Download PDF • 682KB