Question regarding the rate law of a reaction

[ShellDough]

Homework Statement

Data in the table were collected at 300 K for the following reaction:

A(g) + B(g) → products
Concentration of A
1.00
0.100
1.100

Concentration of B
0.100
0.100
1.00

Initial Rate (M/s)
1.29x10^-29
1.33x10^-30
1.30x10^-29

Determine the rate law for the reaction.

Homework Equations

[/B]
Rate = k[A]^m^n, where m and n are the reaction orders.

The Attempt at a Solution

I tried to find the factor [A] increases by for trials 1 and 2, and got the value 0.1. I got a value of 0.103 for the rate that the initial rate changes from trial 1 to 2. From there, I get stuck. I had an equation that I used to try and find the reaction order for [A], but I can't seem to find it anywhere, and any other attempts to find the reaction order give me negative values such as -6, and impossibly large numbers. Please help!

Also, for some reason I can't see the homework template that keeps getting suggested to me. Is there a pdf download anywhere?[/B]

 

[Chestermiller]

You have 3 equation in three unknowns, k, m, and n. The easiest way to do this problem is to take the log of both sides of the rate expression:

log(r) = log(k) + m log(A) + n log B

You have 3 values of A, 3 corresponding values of B, and 3 corresponding values of R. Substituting these into the above equation will give you 3 linear algebraic equations in the 3 unknowns, log (k), m, and n.

 

[epenguin]

Quite simply, comparing the first two when you decrease the concentration of A by a factor of 10, you decrease the rate by practically a factor of 10. So that is telling you that the reaction is first-order in A. Now how about B?