Quiz Three Practice, Chemistry 111, Lycoming College, Feb. 9, 2005, Dr.
Mahler

Fair Game for Friday’s Quiz: New Material – Ch. 13 sections 6, 7, 8, 10 and 11.

Relevant Homework – Ch. 13 Ex. 13.43 (zeroth order), 46 (second order), 52 (kinrtic
theory), 55 , 58 (Arrhenius), 69 (catalyst), 72 (enzymes) and 85d (a&b covered
already).

Practice problems:

1) Possible essay / short answer type questions:

How could you tell if a reaction were zeroth, first, or second order by looking
at a) the half life at various starting concentrations or b) the units of the
rate constant?

If a reaction were either zeroth, first, or second order, what kind of graphs
would you need to make to get linear behavior and tell what the overall order
was?

Write a brief essay explaining catalysts and enzymes and their effect on rates.

2) The second order reaction 2 HI (g) H2 (g) + I2 (g) has a rate constant of 2.4
x 10-6 L/mol s at 575 K. If the starting concentration of HI is 0.153 mol/L, a)
what is the half life, and b) what is the concentration of HI after 50 minutes?

3) The rate constant of the first order reaction 2 N2O (g) 2 N2 (g) + O2 (g) is
0.38/s at 1000. K and 0.87/s at 1030. K. a) Calculate the activation energy of
the reaction. b) What would the rate constant be at 1045 K?

4) The zeroth order reaction A P has a rate constant of 2.75 mmol/L min. If
there are 58.13 mmol of A in 1.000 L of solution initially, a) what is the half
life and b) how long will it take for all the A to react (none left)?