Given the data below, find k.

Question

Given the data below for the reaction, 2 A + 2 B + 4 C => D + E + 3 F,

Experiment	Initial conc of A, mol/L	Initial conc of B, mol/L	Initial conc of C, mol/L	Initial rate, mol/L.s
1	0.1	0.2	0.4	2 x 10-3
2	0.2	0.2	0.4	2 x 10-3
3	0.3	0.4	0.4	4 x 10-3
4	0.4	0.6	0.2	1.5 x 10-3

Calculate the value of k to 3 significant figures

(answer is .0625)

Answer 1

Exp 1 and 2: zero order in

Exp 1 and 3: first order in B

Exp 3 and 4: second order in C

rate = k[B][C]²

k = rate/[B][C]² = 2x10^-3/(0.2)(0.4)²

k = 0.0625 M^-2s^-1