The decomposition of NH3 on a hot platinum surface is zero order with k = 2.5 x 10^-4 mol L^-1 s^-1 for the reaction 2NH3 -> N2 + 3H2. What is the rate of production of H2 in mol L^-1 s^-1?

1. For zero order, rate of reaction $= k = 2.5\times10^{-4}\ \text{mol L}^{-1}\text{s}^{-1}$. 2. Rate $= \dfrac{1}{3}\dfrac{d[H_2]}{dt}$, so $\dfrac{d[H_2]}{dt} = 3k$. 3. $= 3\times2.5\times10^{-4} = 7.5\times10^{-4}\ \text{mol L}^{-1}\text{s}^{-1}$. 4. Distractor A ignores the coefficient 3; distractor B uses the N2 coefficient (2 vs 3 mix-up). _Source: NCERT Class 12 Chemistry Ch 3 "Chemical Kinetics", p.24_