Question

1. Determine the concentrations you would use in order to find the rate law for a given reaction.

a.   Here is one set of conditions – fill out the rest of the table with enough sets of conditions to determine the rate law for the reaction:

A + B à C + D

[A] mol/L	[B] mol/L
1.0	1.0

b.   If you determine that the reaction is first order in A and first order in B, fill out the table below with the rate you would expect for each of the conditions you described in part a. (You will have to copy the conditions from part a to the new table.)

[A] mol/L	[B] mol/L	Initial rate mol/(L×min)
1.0	1.0	2.0

c.   What is the rate equation for the reaction?

d.   What is the value of the rate constant?  Be sure to include appropriate units.

e.   If the reaction is zero order in A and 2^nd order in B, fill out the table with the rates you would expect.

[A] mol/L	[B] mol/L	Initial rate mol/(L×min)
1.0	1.0	2.0

f.    What is the rate equation for the reaction?

g.   What is the value of the rate constant?  Be sure to include appropriate units.

2.   How would you determine the initial rates of the reaction experimentally? What measurements would you record and how would you treat the data?

3.   Lets say you have a new reaction and you think that the reaction has a rate equation:  Rate = k[A]²

However, you only have one set of [A] vs time data. Describe how you would determine what the rate equation is from this one set of data.

4.   For a first order reaction, graph the concentration of reactant A ([A]) vs time. On this same graph indicate two half-life time periods. (That is show where the concentration falls by one half, for two time periods).

5.   The carbon-14 decay rate of a sample obtained from a young live tree is 0.260 disintegrations/(s·g). Another sample prepared from an archaeological excavation gives a decay rate of 0.186 disintegrations/(s·g). The half-life of carbon-14 is 5730 years. What is the age of the object?

Answer 1