İTÜ GELİŞTİRME VAKFI ÖZEL EKREM ELGİNKAN LİSESİ. Term Lesson Unit Subject Date. 2nd Chemistry Unit Review

Transcription

1 İTÜ GELİŞTİRME VAKFI ÖZEL EKREM ELGİNKAN LİSESİ Term Lesson Unit Subject Date 2nd Chemistry Unit Review Name- Surname Class: 10-IB Number: 1. What is the function of iron in the Haber process? A. It shifts the position of equilibrium towards the products. B. It decreases the rate of the C. It provides an alternative reaction pathway with a lower activation energy. D. It reduces the enthalpy change of the 2. Hydrochloric acid is reacted with large pieces of calcium carbonate, the reaction is then repeated using calcium carbonate powder. How does this change affect the activation energy and the collision frequency? Activation energy Collision frequency A. increases increases B. stays constant increases C. increases stays constant D. stays constant stays constant 3. Which statement is true about using sulfuric acid as a catalyst in the following reaction? CH 3 CO CH 3 (aq) + I 2 (aq) H + (aq) CH 3 CO CH 2 I(aq) + HI(aq) I. The catalyst increases the rate of II. III. The catalyst lowers the activation energy for the The catalyst has been consumed at the end of the chemical A. I and II only B. I and III only C. II and III only D. I, II and III (Total 1 mark) IB Questionbank Chemistry 1

2 4. Excess magnesium, was added to a beaker of aqueous hydrochloric acid. A graph of the mass of the beaker and contents was plotted against time (line 1). Mass 1 2 Time What change in the experiment could give line 2? A. The same mass of magnesium in smaller pieces B. The same volume of a more concentrated solution of hydrochloric acid C. A lower temperature D. A more accurate instrument to measure the time 5. Which quantities in the enthalpy level diagram are altered by the use of a catalyst? Enthalpy I II III Time A. I and II only B. I and III only C. II and III only D. I, II and III 6. In a reaction that occurs in 50 g of aqueous solution, the temperature of the reaction mixture increases by 20 C. If 0.10 mol of the limiting reagent is consumed, what is the enthalpy change (in kj mol 1 ) for the reaction? Assume the specific heat capacity of the solution = 4.2 kj kg 1 K 1. A B C. D IB Questionbank Chemistry 2

3 7. Use the average bond enthalpies below to calculate the enthalpy change, in kj, for the following H 2 (g) + I 2 (g) 2HI(g) A B. +10 C. 10 D. 290 Bond Bond energy / kj mol 1 H H 440 I I 150 H I How much energy, in joules, is required to increase the temperature of 2.0 g of aluminium from 25 to 30 C? (Specific heat of Al = 0.90 J g 1 K 1 ). A B. 4.5 C. 9.0 D Which combination is correct for a chemical reaction that absorbs heat from the surroundings? Type of reaction ΔH at constant pressure A. Exothermic Positive B. Exothermic Negative C. Endothermic Positive D. Endothermic Negative 10. Using the equations below: C(s) + O 2 (g) CO 2 (g) H ο = 394 kj mol 1 Mn(s) + O 2 (g) MnO 2 (s) H ο = 520 kj mol 1 What is H, in kj, for the following reaction? A. 914 B. 126 C. 126 MnO 2 (s) + C(s) Mn(s) + CO 2 (g) IB Questionbank Chemistry 3

4 D Which statement is always correct for a chemical reaction at equilibrium? A. The rate of the forward reaction equals the rate of the reverse B. The amounts of reactants and products are equal. C. The concentration of the reactants and products are constantly changing. D. The forward reaction occurs to a greater extent than the reverse 12. An increase in temperature increases the amount of chlorine present in the following equilibrium. PCl 5 (s) PCl 3 (l) + Cl 2 (g) What is the best explanation for this? A. The higher temperature increases the rate of the forward reaction only. B. The higher temperature increases the rate of the reverse reaction only. C. The higher temperature increases the rate of both reactions but the forward reaction is affected more than the reverse. D. The higher temperature increases the rate of both reactions but the reverse reaction is affected more than the forward. 13. What will happen when at a constant temperature, more iodide ions, I, are added to the equilibrium below? I 2 (s) + I (aq) I 3 (aq) A. The amount of solid iodine decreases and the equilibrium constant increases. B. The amount of solid iodine decreases and the equilibrium constant remains unchanged. C. The amount of solid iodine increases and the equilibrium constant decreases. D. The amount of solid iodine increases and the equilibrium constant remains unchanged. IB Questionbank Chemistry 4

5 14. The sequence of diagrams represents the system as time passes for a gas phase reaction in which reactant X is converted to product Y. Diagram 1 t = 7 seconds Diagram 2 t = 5 minutes Diagram t = 10 minutes Diagram 4 t = 5 days Time, t X = Y = Which statement is correct? A. At t = 5 days the rate of the forward reaction is greater than the rate of the backward B. At t = 7 seconds the reaction has reached completion. C. At t = 10 minutes the system has reached a state of equilibrium. D. At t = 5 days the rate of the forward reaction is less than the rate of the backward 15. What changes occur when the temperature is increased in the following reaction at equilibrium? Br 2 (g) + Cl 2 (g) 2BrCl(g) H ο = +14 kj mol 1 Position of equilibrium Value of equilibrium constant A. Shifts towards the reactants Decreases B. Shifts towards the reactants Increases C. Shifts towards the products Decreases D. Shifts towards the products Increases IB Questionbank Chemistry 5