Rate law equation????

Question

Nitric Oxide, NO(g), reacts with chlorine gas, Cl2(g), in the reaction:

2NO(g) + Cl2(g) --> 2NOCl(g)

The following data was collected in a study of rate of reaction for this reaction:

Trial Initial [NO] mol/L Initial [Cl2] mol/L Reaction rate

1 0.10 0.10 1.8*10^-2

2 0.10 0.20 3.6*10^-2

3 0.20 0.20 1.44*10^-1

Write the rate law equation for this reaction. Also, include the numerical value of k. the units for reaction rate is mol/Ls

Answer 1

rate law = k[NO]^2[CL2]

k=18

[NO]^2 because by doubling NO from 0.10 in trial 1 to 0.20 in trial 2, it increases the rate by 4, because x^2, (ex. 1^2=1, 2^2=4, thus 1->4) all while Cl2 stays the same (0.2). Likewise, doubling Cl2 increases the rate by 2 only, while [NO] stays constant, thus it is [CL2]

After figuring out rate law, plug in any trial set of values into the rate law to get k. (ex. (3.6x10^-2)/[(0.10)x(0.20)^2]