Advanced Placement Chemistry

1967 Free Response Questions


1. When propane is burned in pure oxygen, the reaction proceeds according to the equation:

C3H8(g) + 5 O2(g) ---> 3 CO2(g) + 4 H2O(g)

If such an oxidation is carried out on a gaseous mixture prepared by mixing 6.1 grams of C3H8 and 11.0 liters of O2 measured at 1.0 atmosphere and 150 °C, what will be the total final volume under the same conditions of measurement after the reaction is complete?

2. The Kb of ammonia is 1.8 x 10¯5; the Ksp of Mg(OH)2 is 1.1 x 10¯11.

(a) What is the pH of a solution which is 0.030 molar with respect to ammonia and 0.050 molar with respect to ammonium chloride?
(b) If 0.20 liter of this solution is mixed with 25 milliliters of 0.084-molar sodium hydroxide solution, what is the resulting pH?
(c) Carry out calculations to determine whether a precipitate of magnesium hydroxide should be expected to form if equal volumes of the solution prepared in (b) and a 0.020-molar solution of magnesium chloride are mixed.

Questions 3-5 are not available.

6. PbCl2(s) moist + H2S(g) --->

7. NaOH(s) moist + CO2(g) --->

8. AgCl(s) + NH3(aq) --->

9. MnO4¯(aq) + H+(aq) + I¯(aq) --->

10. PCl3 + H2O --->

11. H2O2(aq) (heated) --->

12. Hg(l) + HNO3 (concentrated) --->

13. BF3(g) + (CH3)3N(g) --->

14. The equation of state, pV = nRT, applies to an ideal gas. Discuss two factors which cause nonideality.

15. Two substances with the formula [Co(NH3)4Cl2]Cl have been isolated. Both have the same magnetic susceptibility. What structures consistent with these data can you suggest for the two substances?

16. Suppose that you are given the value of the first ionization potential for a metal. Using this factor, what other information would you need to determine the value of the oxidation potential for the formation of the univalent cation of the metal?

17. In general, the value of the equilibrium constant for any chemical system in equilibrium varies with the temperature. For a specific system in equilibrium, what determines the effect a temperature increase will have on the value of the equilibrium constant?

18. For the titration of 0.1-molar acetic acid with 0.1-molar sodium hydroxide, what factors need to be considered in selecting an indicator?

19. Cite some of the facts that support the theory of hydrogen bonding.