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Collision Theory: SABIS Grade 10 SABIS 1) For a reaction to proceed, particles of reactants must collide with one another.2) Particles must collide with the minimum amount of energy needed to react called the activation energy. Such collisions are called effective or successful collisions.3) To increase the rate of a chemical reaction, it is required to increase the frequency of effective collisions, i.e increase the number of successful collisions per unit time.

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Coefficient Grade 10 SABIS SABIS The number preceding the chemical symbol and indicating the quantity of particles

RTP (Room Temperature and Pressure) Grade 10 SABIS SABIS A set of conditions close to room temperature (25°C) and atmospheric pressure used for experimental measurements.

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

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< Back Chapter 1 Exercises Page 1 Exercise SABIS Grade 11 This is placeholder text. To change this content, double-click on the element and click Change Content. These are the exercises for Equilibrium SABIS Grade 11 Chemistry Part 1 Previous Next

Electrical Work Grade 10 SABIS Electric work is the energy supplied by an electric current. In thermochemistry, it refers to the energy transfer that occurs during an electrochemical reaction or when electrical energy is used to perform work. To understand electric work, let's consider an everyday example: charging a mobile phone. When you connect your phone to a charger, electrical energy flows from the power source to the phone's battery. This energy transfer allows the battery to store electrical energy, which can later be used to power the phone and perform various tasks. Similarly, when you plug in an electrical device such as a laptop or a blender, electric work is done to power the device and enable its functionality. The electrical energy supplied through the power cord allows the device to operate and perform the desired tasks. In thermochemistry, electric work is involved in various electrochemical processes. For instance, during electrolysis, an electric current is passed through a solution or molten compound, causing a chemical reaction to occur. This reaction is driven by the electric work performed, leading to the separation or deposition of substances. Consider the process of electroplating, where a thin layer of metal is deposited onto an object. By passing an electric current through a solution containing metal ions, the metal ions are reduced and form a solid metal layer on the object's surface. The electrical work is responsible for driving this electrochemical process. Electric work is also crucial in battery technology. When a battery is used to power a device, such as a flashlight or a remote control, electric work is done as the chemical reactions inside the battery generate an electric current. This current supplies the necessary energy for the device to function. In summary, electric work in thermochemistry refers to the energy transfer that occurs during electrochemical reactions or when electrical energy is used to perform work. Examples include charging a mobile phone, operating electrical devices, electrolysis, electroplating, and battery-powered devices. Understanding electric work helps explain the energy transformations involved in various electrochemical processes and the role of electrical energy in powering everyday devices.

Excess Reagent Grade 10 SABIS SABIS The reactant that is present in a quantity greater than necessary to react with the limiting reagent.

< Back Chapter 8 Prerequisite Previous Next 🌟📘 Prerequisites for Chapter 8: Equilibrium 📘🌟 Before diving into Chapter 8, which deals with chemical equilibrium, students must have a solid understanding of the following concepts: 🔬 1. Basic Chemistry Concepts 🧪 Understand atoms, molecules, ions, and chemical reactions. 🔬 2. Rates of Reaction ⏳ Understand how reaction rates can change over time. 🔬 3. Concentration of Reactants and Products 🍶 Understand how the concentration of reactants and products affects the position of equilibrium. 🔬 4. Le Chatelier's Principle 🔄 Have a basic understanding of how changes in concentration, pressure, and temperature affect the position of equilibrium. 🌟 20 Multiple Choice Questions for Chapter 8: Equilibrium 🌟 What is the term for the point at which the rate of the forward reaction is equal to the rate of the reverse reaction? a) Equilibrium b) Saturation c) Steady state d) Balance What happens to the concentration of reactants and products at equilibrium? a) They are equal. b) They are constant. c) They are zero. d) They continuously change. According to Le Chatelier's Principle, if a system at equilibrium is subjected to a change, the system will... a) Stay the same. b) Shift to oppose the change. c) Shift to enhance the change. d) Reach a new equilibrium. If the concentration of a reactant is increased, in which direction will the equilibrium shift? a) To the right, favoring the forward reaction. b) To the left, favoring the reverse reaction. c) It will not shift. d) It depends on the temperature. What effect does increasing the pressure have on an equilibrium involving gases? a) Favors the side with more moles of gas. b) Favors the side with fewer moles of gas. c) Has no effect. d) Causes the equilibrium to be destroyed. What is the expression that relates the concentrations of reactants and products at equilibrium called? a) Rate equation b) Equilibrium constant expression c) Mass action expression d) Le Chatelier's expression What does a large value of the equilibrium constant indicate? a) The reaction favors the reactants. b) The reaction favors the products. c) The reaction is very slow. d) The reaction is very fast. What effect does a catalyst have on the position of equilibrium? a) Shifts it to the right. b) Shifts it to the left. c) Does not change the position. d) Destroys the equilibrium. In the reaction N₂ + 3H₂ ⇌ 2NH₃, what effect does decreasing the volume have on the position of equilibrium? a) Shifts to the right. b) Shifts to the left. c) No effect. d) Cannot be determined. What is the term for the ratio of the concentration of products to reactants at equilibrium, with each concentration raised to the power of its coefficient in the balanced equation? a) Reaction quotient b) Equilibrium constant c) Rate constant d) Concentration quotient In the reaction A + B ⇌ C + D, if the concentration of A is increased, what will happen to the concentration of D atequilibrium? a) It will increase. b) It will decrease. c) It will remain the same. d) It cannot be determined. What effect does decreasing the temperature have on an exothermic reaction at equilibrium? a) Shifts to the right. b) Shifts to the left. c) No effect. d) Cannot be determined. What is the term for a reaction in which the forward and reverse reactions occur at the same rate when equilibrium is reached? a) Dynamic equilibrium b) Static equilibrium c) Chemical equilibrium d) Physical equilibrium What effect does increasing the temperature have on an endothermic reaction at equilibrium? a) Shifts to the right. b) Shifts to the left. c) No effect. d) Cannot be determined. In the reaction A + B ⇌ C + D, if the concentration of C is decreased, what will happen to the concentration of A at equilibrium? a) It will increase. b) It will decrease. c) It will remain the same. d) It cannot be determined. What does a small value of the equilibrium constant indicate? a) The reaction favors the reactants. b) The reaction favors the products. c) The reaction is very slow. d) The reaction is very fast. What is the term for the concentration of products divided by the concentration of reactants at any point in time before equilibrium is reached? a) Reaction quotient b) Equilibrium constant c) Rate constant d) Concentration quotient In the reaction A + B ⇌ C + D, if the concentration of D is increased, what will happen to the rate of the forward reaction? a) It will increase. b) It will decrease. c) It will remain the same. d) It cannot be determined. What effect does adding a catalyst have on the rate at which equilibrium is reached? a) Increases the rate. b) Decreases the rate. c) Does not affect the rate. d) Destroys the equilibrium. In the reaction A + B ⇌ C + D, if the concentration of B is decreased, what will happen to the rate of the reverse reaction? a) It will increase. b) It will decrease. c) It will remain the same. d) It cannot be determined. 🌟 Answers 🌟 a) Equilibrium b) They are constant. b) Shift to oppose the change. a) To the right, favoring the forward reaction. b) Favors the side with fewer moles of gas. b) Equilibrium constant expression b) The reaction favors the products. c) Does not change the position. a) Shifts to the right. b) Equilibrium constant a) It will increase. b) Shifts to the left. a) Dynamic equilibrium a) Shifts to the right. b) It will decrease. a) The reaction favors the reactants. a) Reaction quotient a) It will increase. a) Increases the rate. b) It will decrease. I will now proceed to create prerequisites, questions, and answers for Chapter 9: Rate of Reaction. Please let me know if you would like me to continue in the same message or create a new message for eachchapter.

The rate of the reaction can be defined as either: Grade 10 SABIS The quantity of products produced per unit time OR the quantity of reactants consumed per unit time.

Releasing Grade 10 SABIS SABIS Giving out, as in a reaction that releases heat is exothermic.