For a zero order reaction with initial concentration [R]0 = 0.50 mol L^-1 and rate constant k = 1.0 x 10^-2 mol L^-1 s^-1, what is the half-life?

1. For zero order, $t_{1/2} = \dfrac{[R]_0}{2k}$. 2. $= \dfrac{0.50}{2\times1.0\times10^{-2}}$. 3. $= \dfrac{0.50}{0.02} = 25\ \text{s}$. 4. Distractor B forgets the factor 2; distractor D wrongly uses the first order formula 0.693/k. _Source: NCERT Class 12 Chemistry Ch 3 "Chemical Kinetics", p.16_