Use this information to write a rate law for this reaction, and calculate the value of the rate constant k

Question

Some measurements of the initial rate of a certain reaction are given in the table below.

[N2]	[H2]	initial rate of reaction
1.36 M	0.913 M	0.484 M/s
1.36 M	4.35 M	11.0 M/s
4.53 M	0.913 M	1.61 M/s

Use this information to write a rate law for this reaction, and calculate the value of the rate constant k.

Round your value for the rate constant to 2 significant digits. Also be sure your answer has the correct unit symbol. 

rate = k

k =

Answer 1

Comparing trial 1 to trial 2, [N₂] is constant and [H2] increases by 4.76x. The rate increases by 22.7x. This tells us the reaction is 2nd order in H₂.

Comparing trial 1 to trial 3, [H₂] is constant and [N2] increases by 3.33x. The rate increases by 3.33x. This tells us the reaction is 1st order in [N₂].

Now we can write the rate law as ...

Rate = k[N₂][H₂]²

Use any trial and plug in the values and solve for k. We will use trial 1...

0.484 M/s = k(1.36 M)(0.913 M)²

0.484 M/s = 1.134 M³k

k = 0.43 M^-2s^-1