2013 AP Chemistry化学真题系列之简答题免费下载

历年AP Chemistry化学系列

真题与答案下载

翰林国际教育全网首发

力争超快速发布最全资料

助你在升学路上一帆风顺

为你的未来保驾护航

2013 AP Chemistry Free-Response Questions Free Download

2013 AP 化学简答题部分免费下载

考试时会提供花常用的等式与常量

以及化学元素周期表

此套Section II试卷共6题

每道大题含有不同数量的小题

共计时95分钟

Part A计55分钟，第1-3题各20分

Part B计40分钟，第四题值10分，第5第6题各15分

完整版下载链接见文末

部分真题预览：

Section II, Part A,YOU MAY USE YOUR CALCULATOR FOR PART A可使用计算器：

1）Answer the following questions about the solubility of some fluoride salts of alkaline earth metals.

1. A student prepares 100. mL of a saturated solution of MgF₂ by adding 0.50 g of solid MgF₂ to 100. mL of distilled water at 25°C and stirring until no more solid dissolves. (Assume that the volume of the undissolved MgF₂ is negligibly small.) The saturated solution is analyzed, and it is determined that [F^-] in the solution is 2.4 × 10^-3 M.
   1. Write the chemical equation for the dissolving of solid MgF₂ in water.
   2. Calculate the number of moles of MgF₂ that dissolved.
   3. Determine the value of the solubility-product constant, K_sp , for MgF₂ at 25°C.
2.  A beaker contains 500. mL of a solution in which both Ca²⁺(aq) and Ba²⁺(aq) are present at a concentration of 0.10 M at 25°C. A student intends to separate the ions by adding 0.20 M NaF solution one drop at a time from a buret. At 25°C the value of K_sp for CaF₂ is 3.5 × 10^-11; the value of K_sp for BaF₂ is 1.8 × 10^-6.

i. Which salt will precipitate first, CaF₂ or BaF₂ ? Justify your answer.

For parts (b)(ii) and (b)(iii) below, assume that the addition of the NaF solution does not significantly affect the total volume of the liquid in the beaker.

ii. Calculate the minimum concentration of F(aq) necessary to initiate precipitation of the salt selected in part (b)(i).

iii. Calculate the minimum volume of 0.20 M NaF that must be added to the beaker to initiate precipitation of the salt selected in part (b)(i).

1. There are several ways to dissolve salts that have limited solubility. Describe one procedure to redissolve the precipitate formed in part (b).

完整版真题资料可以底部二维码免费领取↓↓↓