Chapter 18 Review “Reaction Rates and Equilibrium”

Possible Essays List the four factors that affect reaction rate and describe the effects that they have. What are the three stresses that can change the equilibrium of a reaction and explain how the stress would be relieved. What are the two factors that determine the spontaneity of a reaction and describe the favorable outcomes. Make sure to include how Gibbs Free Energy comes into play. What is the difference between a spontaneous and nonspontaneous reaction? Why can a spontaneous reaction appear to be nonspontaneous?

Chapter 18 Review Energy that is available to do work is called ____. What is the name of the minimum energy that colliding particles must have in order to react?

Chapter 18 Review A substance that interferes with a catalyst is a(n) ____. What is the arrangement of atoms at the peak of an energy barrier? At equilibrium, what is the rate of production of reactants compared with the rate of production of products?

Chapter 18 Review What is the equilibrium constant expression for the following reaction: C(s) + O2(g) ↔ CO2(g) Which of the following is true about the combustion of carbon: a) the reaction is spontaneous, or b) entropy decreases? The rate of a chemical reaction normally ____ as reactant concentration increases.

Chapter 18 Review Why does a higher concentration make a reaction faster? The amount of disorder in a system is measured by its ____. What units represent a reaction rate? For a complex reaction, the reaction progress curve has several ____.

Chapter 18 Review What happens to a reaction at equilibrium when more reactant is added to the system? Which reaction results in the greatest increase in entropy: a) A → B, or b) A → 2B If a reaction has an equilibrium constant (Keq) just greater than 1, how do we interpret that information?

Chapter 18 Review A catalyst works by ____. If sulfur dioxide and oxygen can be made into sulfur trioxide, what is the reverse reaction? Which variable is NOT required to calculate the Gibbs free-energy change for a chemical reaction: a) change in enthalpy, or b) temperature in oC?

Chapter 18 Review What is the effect of adding more water to the following equilibrium reaction: CO2 + H2O ↔ H2CO3 In an endothermic reaction at equilibrium, what is the effect of raising the temperature? The energy that is available to do work in a reaction is called ____.

Chapter 18 Review What is the numerical value (+ or -) of Gibbs free-energy change for a spontaneous reaction? At what stage of a reaction do atoms have the highest energy? Which of the following systems has the highest entropy: a) 10 mL of water at 50 oC, or b) 10 mL of water at 100 oC?

Chapter 18 Review What happens to a catalyst in a reaction? An elementary reaction converts reactants to products in ____. Activation energy is ____.

Chapter 18 Review Consider the reaction: N2(g) + 3H2(g) ↔ 2NH3(g) What is the effect of decreasing the volume on the contained gases? Spontaneous reactions always ____ free energy. Why does a higher temperature cause a reaction to go faster?

Chapter 18 Review What 2 factors determine whether or not a reaction is spontaneous? What physical state of nitrogen has the highest entropy? What is another name for the catalysts in your body?

Chapter 18 Review What is the order of the following reaction: A + 2B → C + D Why does a catalyst cause a reaction to proceed faster? In an equilibrium reaction with a Keq of 1 x 108, the ____ are favored. Which of the following explains why melting of ice is spontaneous at room temperature and pressure: a) it is accompanied by an increase in entropy, or b) it is accompanied by an increase in energy?

Chapter 18 Review The Keq of a reaction is 4 x 10-7. At equilibrium, the ____ are favored. Another name for the activated complex is ____. Which change would shift the following reaction to the right: 4HCl(g) + O2(g) ↔ 2Cl2(g) + 2H2O(g) a) decrease of pressure, or b) increase of pressure?

Chapter 18 Review In which of these systems is the entropy decreasing: a) salt dissolving in water, or b) a liquid cooling? Given: 2NClO(g) ↔ 2NO(g) + Cl2(g) An analysis of the equilibrium mixture in a 1 L flask is: NClO = 1.6 mol; NO = 6.4 mol; Cl2 = 0.49 mol. Calculate the value of Keq.

Chapter 18 Review In a two-step reaction mechanism, how many elementary reactions occur? The Ksp of calcium hydroxide is 6.5 x 10-6. If 0.10 mol of sodium hydroxide is added to 1 L of 0.0010 M Ca(OH)2, what is the final concentration of the calcium ion?

Chapter 18 Review A mixture of hydrogen and iodine are in equilibrium with hydrogen iodide, as shown in the equation: H2 + I2 ↔ 2HI Calculate the concentration of HI when the Keq is 1 x 105, the equilibrium concentration of H2 is 0.04 M, and the equilibrium concentration of I2 is 0.009 M.

Chapter 18 Review End of Chapter 18 Review