Question

The rate constant of reaction $2A+B\to C$ is $2.57\times {10}^{-5}$ $litre$ ${mole}^{-1}$ ${sec}^{-1}$ after $10$ sec. $2.65\times {10}^{-5}$ $litre$ ${mole}^{-1}$ ${sec}^{-1}$ after $20$ sec and $2.55\times {10}^{-5}litre.$ ${mole}^{-1}$ ${sec}^{-1}$ after $30$ sec. The order of the reaction is:

• A. 0
• B. 1
• C. 2
• D. 3

Answer 1

Answer: (C)

2

Units of rate constant are given by $mo{l}^{1-n}l{t}^{n-1}se{c}^{-1}$

where $n=$ order of the reaction

From the given units, we get $n=2$.

Hence, given reaction is a 2nd order reaction.