2021知到答案【Basic Chemistry 基础化学】智慧树网课章节测试答案

1、第 页2021知到答案【 Basic Chemistry 基础化学 】智慧树网课章节测试答案 第二章 章节测试第七章 章节测试第八章 章节测试 1、选择题:A solution is prepared by dissolving 15.0 g of NH3 in 250 g of water. The density of the resulting solution is 0.974 g/mL. The mole fraction of NH3 in the solution is _.选项：A:0.922B:16.8C:0.0597D:0.94E:0.064答案: 【0.0597】2、选择

2、题:The vapor pressure of pure water at 25 C is 23.8 torr. Determine the vapor pressure (torr) of water at 25 C above a solution prepared by dissolving 35 g of urea (a non-volatile, non-electrolyte, MW = 60.0 g/mol) in 75 g of water.选项：A:3.3B:27C:0.88D:21E:2.9答案: 【21】3、选择题:The freezing point of ethano

3、l (C2H5OH) is -114.6 C. The molal freezing point depression constant for ethanol is 2.00 C/m. What is the freezing point (C) of a solution prepared by dissolving 50.0 g of glycerine (C3H8O3 a nonelectrolyte) in 200 g of ethanol?选项：A:-5.42B:-114.6C:-120D:-115E:-132.3答案: 【-120】4、选择题:A solution is prep

4、ared by dissolving 6.00 g of an unknown nonelectrolyte in enough water to make 1.00 L of solution. The osmotic pressure of this solution is 0.750 atm at 25.0 C. What is the molecular weight (g/mol) of the unknown solute?选项：A:5.12 10-3B:30.6C:195D:110E:16.4答案: 【195】5、选择题:The principal reason for the

5、extremely low solubility of NaCl in benzene (C6H6) is the _.选项：A:increased disorder due to mixing of solute and solventB:strong solvent-solvent interactionsC:weak solvation of Na+ and Cl by C6H6D:hydrogen bonding in C6H6E:strength of the covalent bond in NaCl答案: 【weak solvation of Na+ and Cl by C6H6

6、】6、选择题:Pairs of liquids that will mix in all proportions are called _ liquids.选项：A:unsaturatedB:polar liquidsC:miscibleD:saturatedE:supersaturated答案: 【miscible】7、选择题:The solubility of oxygen gas in water at 25 C and 1.0 atm pressure of oxygen is 0.041 g/L The solubility of oxygen in water at 3.0 atm

7、 and 25 C is _ g/L.选项：A:0.014B:0.041C:0.31D:3E:0.12答案: 【0.12】8、选择题:A sample of potassium chlorate (15.0 g) is dissolved in 201 g of water at 70 C with precautions taken to avoid evaporation of any water. The solution is cooled to 30.0 C and no precipitate is observed. This solution is _.选项：A:saturatedB:unsaturatedC:miscibleD:hydratedE:supersaturated答案: 【unsaturated】9、选择题:The concentration of lead nitrate (Pb(NO3 )2) in a 0.726 M solution is _ molal. The density of the solution is 1.202 g/mL.选项：A:0.65B:1.928C:0.819D:0.476E:0.755答案: 【0.755】10、选择题:The concentration of