A study of the decomposition of azomethane, CH3NNCH3(g) C2H6(g)+ N2(g) gave the following concentrations of azomethane

Question:

A study of the decomposition of azomethane,
CH3NNCH3(g) → C2H6(g)+ N2(g)
gave the following concentrations of azomethane at various times:
Time [CH3NNCH3]
0 min………. 1.50 × 102 M
10 min………. 1.29 × 102 M
20 min………. 1.10 × 102 M
30 min……….. 0.95 × 102 M
Obtain the average rate of decomposition in units of M/s for each time interval.