JEE Advanced Model Paper 1 with solutions for online practice

The reduction of nitric oxide gas by hydrogen gas as represented below:
2NO + 2H2 → N2 + 2H2O takes place in the sequence of following steps:
I . NO + NO ⇌ N2O2 ( fast and reversible)
II . N2O2 + H2 → N2O + H2O (slow)
III . N2O + H2 → N2 + H2O (fast)
The reaction follows the rate law +

d[N2]

dt

= k [NO]2 [H2]
If k = 6.0 × 10−4 mole−2 L2min−1 and k2 the rate constant of Step II be 3.0 × 10−2 mole−1 L min−1 , the numerical value of the equilibrium constant (kc) the StepI is 2 × 10−a . The value of 'a' is