Start learning →

A rate constant is found to have units L mol^-1 s^-1. What is the order of the reaction?

AFirst order
BZero order
CThird order
DSecond order
Answer & Solution
Correct answer: D. Second order
1. For an order-n reaction, units of k are $(\text{mol L}^{-1})^{1-n}\text{s}^{-1}$. 2. For second order ($n=2$): $(\text{mol L}^{-1})^{-1}\text{s}^{-1} = \text{L mol}^{-1}\text{s}^{-1}$. 3. This matches the given units, so the reaction is second order. 4. First order would be s^-1 and zero order mol L^-1 s^-1, neither matching. _Source: syllabus Chemistry Ch 3 "Chemical Kinetics", p.8_
Practise this question with Quill — ISC Class 12 →

Keep practising Chemical Kinetics

Browse all Chemical Kinetics questions for ISC Class 12, or explore more Chemistry topics.

Start a Chemical Kinetics lesson →