Name:…………………………………..………………….
 
Exam 1                         Duration 90 minutes

Chem 102

Answer all the questions in the space provided.

  1. Define the following terms and give appropriate examples in each case.

a)      Saturated

b)      Solution

c)      Miscible

d)      Osmosis

e)      Colligative Property                                                                              [10]

 

 

 

 

 

 

 

 

 

 

 

 

 

                                                                                                                

  1. A solution of Hydrochloric acid contains 45% HCl by mass.

a)      Calculated the mole fraction of HCl in the solution.

b)      Calculated the molality of HCl in the solution.                            [10]

 

 

  1. A 3.0 g sample of ground water contains 3.5 ppm of arsenic ion.  How many grams of arsenic are in the sample?                                                                        [10]

 

 

  1. In three different experiments, the following data were obtained for the reaction

A         +          B                   C

 

Experiment No

Initial Concentration of [A] M

Initial Concentration of [B] M

Initial Rate M/s

1

0.20

1.00

5.0 X10-2

2

0.20

2.00

2.0 X10-1

3

0.40

2.00

4.0 X 10-1

 

a)      Determine the Rate Law for the reaction.

b)      The magnitude of the Rate Constant.

c)       The rate of reaction when [A] is 0.50 M and [B] is 3.00 M.

d)      What is the overall order of reaction                                                           [20]

 

 

  1. A solution contains 10.0 g of KOH and 900 mL of water at 20 oC.  The volume of solution is 904.7 mL.

a)      Which component of the solution is the solute?

b)      Which is the solvent?

c)      What is the molarity of the solution?

d)      What is the mass percentage of KOH?

e)      What is the mole fraction of KOH?

f)        What is the molality of solution?                                                            [20]

 

  1. Automotive antifreeze consists of ethylene glycol (C2H6O2), a nonvolatile nonelectrolyte.  Calculate the boiling point and freezing point of a 25.0 mass % solution of ethylene glycol in water.                                                             [5]

 

  1. Predict whether each of the following substances is more likely to dissolve in carbon tetrachloride (CCl4) or in water: C6H14, Na2SO4, HCl, F2.                      [5]

 

  1. The decomposition of N2O5 proceeds according to the following equation:

2N2O5 (g)             4NO2(g)           +          O2(g)               

 

If the rate of decomposition of N2O5 at a particular instant in a reaction vessel is 4.0 x 10-6 M/s, what is the rate of appearance of (a) NO2 and (b) O2?                                          [10]

 

 

  1. Why does a 0.10 m aqueous solution of NaCl have a higher boiling point than a 0.10 m aqueous solution of C6H12O6?                                                                     [5]

 

 

 

 

 

 

 

 

 

 

 

 

 


  1. What factors affect the rate of reaction and why?                                               [5]

 

 

Bonus Question

 

Briefly explain with the use of diagrams how a Biological Catalyst works.                       [5]