ANSWER ALL QUESTIONS

1. The data below were collected for the reaction: BrO3–

+ 5 Br–

+ H3O+ → 3 Br2 + 9 H2O

Exp Initial Concentration of Reactants (mol/L) Initial Rate (mol/L•s)

BrO3– Br

– H3O

+

1 0.10 0.10 0.10 1.2

2 0.20 0.10 0.10 2.4

3 0.10 0.30 0.10 3.6

4 0.20 0.10 0.15 5.4

a. Determine the rate law for this reaction.

b. Calculate the value of k for this reaction and express it with the correct units.

Chemistry Unit

Session 2013/2014

Semester 2

Sample QUIZ Paper

NAME : ________________________________________________

MATRIC NUMBER : ________________________________________________

CLASS : ________________________________________________

NAME OF TUTOR : _____________________________________________

2. The data below were collected for the reaction at 327 °C: H2 (g) + I2 (g) → 2 HI (g)

Experiment Initial [H2], M Initial [I2], M Initial Rate, mol/L•s

1 0.113 0.110 3.01 x 10–4

2 0.220 0.330 1.76 x 10–3

3 0.550 0.110 1.47 x 10–3

a. Determine the rate law for this reaction.

b. Calculate the value of k for this reaction and express it with the correct units.

Answer:

1.a. Rate = k[BrO3–][Br

–][H3O

+]

2

note: you will not receive full credit if you only write k[BrO3–][Br

–][H3O

+]

2, of if you

capitalize K (that’s a different constant!), or if you write in the value of k instead of just k. The great thing about a rate law is that it works at any temperature, but k is different at different temperatures.

b. k = 1.2 x 104

L3/mol

3 s

2 .a. Rate = k[H2][I2]

b. k = 0.0243 L/mol s