Base your answers to questions 1 and 2 on the information below. Given the reaction at equilibrium: Base your answers to questions 5 through 7 on the

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10 Base your answers to questions 1 and 2 on the information below. Given the reaction at equilibrium: Base your answers to questions 5 through 7 on the potential energy diagram and the equation below. 2NO 2 (g) + 7H 2 (g) 2NH 3 (g) + 4H 2 O(g) kj 1. Complete the potential energy diagram above for the forward reaction. Be sure your drawing shows the activation energy and the potential energy of the products. 2. Explain, in terms of Le Chatelier s principle, why the concentration of NH 3 (g) decreases when the temperature of the equilibrium system increases. 3. Base your answer to the following question on the information below. 5. The letter B represents which chemical formula or formulas in the equation? 6. If kilojoules are absorbed, how many moles of C (g) are produced? 2 H 2 7. Describe how the potential energy diagram will change if a catalyst is added. A student wishes to investigate how the reaction rate changes with a change in concentration of HCl(aq). Given the reaction: Zn(s) + HCl(aq) H 2 (g) + ZnCl 2 (aq) Describe the effect of increasing the concentration of HCl(aq) on the reaction rate and justify your response in terms of collision theory. 4. Given the reaction at 1 atm and 298 K: The heat of reaction, ΔH, is (1) negative and the reaction is spontaneous (2) negative and the reaction is not spontaneous (3) positive and the reaction is spontaneous (4) positive and the reaction is not spontaneous

11 8. Given the data table below showing the solubility of salt X: a Which salt on Table G is most likely to be salt X? b Scale and label the y-axis including appropriate units. c Plot the data from the data table. Surround each point with a small circle and draw a best-fit curve for the solubility of salt X. d Using your graph, predict the solubility of salt X at 50ºC. e If the pressure on the salt solution was increased, what effect would this pressure change have on the solubility of the salt? 9. A student wishes to determine how the rate of reaction of magnesium strips with hydrochloric acid, HCl(aq), varies as a function of temperature of the HCl(aq). Give two additional factors, other than the temperature, that could affect the rate of reaction and must be held constant during the experiment. 10. Given the reaction at equilibrium: N 2 (g) + 3 H 2 (g) 2 NH 3 (g) kj a. State the effect on the number of moles of N 2 (g) if the temperature of the system is increased. b. State the effect on the number of moles of H 2 (g) if the pressure on the system is increased. c. State the effect on the number of moles of NH 3 (g) if a catalyst is introduced into the reaction system. Explain why this occurs. 11. Base your answer to the following question on the information and equation below. Human blood contains dissolved carbonic acid, H 2 CO 3, in equilibrium with carbon dioxide and water. The equilibrium system is shown below. H 2 CO 3 (aq) CO 2 (aq) + H 2 O( ) Explain, using LeChatelier s principle, why decreasing the concentration of CO 2 decreases the concentration of H 2 CO 3.

12 Base your answers to questions 12 through 14 on the potential energy diagram below. 12. What is the heat of reaction for the forward reaction? 13. What is the activation energy for the forward reaction with the catalyst? 14. Explain, in terms of the function of a catalyst, why the curves on the potential energy diagram for the catalyzed and uncatalyzed reactions are different.