For the chemical reaction

$N_2(g)+3H_2(g) \rightleftharpoons 2NH_3(g)$

the correct option is:

(1) $-{1\over3}{d[H_2]\over dt}=- {1\over2} {d[NH_3]\over dt}$

(2) $-{d[N_2]\over dt}=2 {d[NH_3]\over dt}$

(3) $-{d[N_2]\over dt}={1\over2} {d[NH_3]\over dt}$

(4) $3{d[H_2]\over dt}=2 {d[NH_3]\over dt}$

$N_2(g)+3H_2(g) \rightleftharpoons 2NH_3(g)$

the correct option is:

(1) $-{1\over3}{d[H_2]\over dt}=- {1\over2} {d[NH_3]\over dt}$

(2) $-{d[N_2]\over dt}=2 {d[NH_3]\over dt}$

(3) $-{d[N_2]\over dt}={1\over2} {d[NH_3]\over dt}$

(4) $3{d[H_2]\over dt}=2 {d[NH_3]\over dt}$