Let, the order of reaction wrt [NH4+],[NO2−] be xand y respectively. Then, rate law, r=k[NH4+]×[NO2]γ On substituting the values of different experiments, (i) 0.020=k[0.010]x[0.020]γ (ii) 0.020=k[0.015]x[0.020]γ (iii) 0.005=k[0.010]x[0.010]γ Dividing Eq. (i) by Eq. (ii) gives (‌
0.020
0.030
)=(‌
0.010
0.015
)x (‌
2
3
)1=(‌
2
3
)x or x=1 Dividing Eq. (i) by (iii) gives ‌
0.020
0.005
=(‌
0.020
0.010
)y 4=2y (2)2=(2)y or y=2 On substituting the values of x and y in the rate law, we get r=k[NH4+][NO2−]2