The rate law for the reaction $\mathrm{A}+\mathrm{B} \rightarrow$ product is given by rate $=k[A][B]$…

The rate law for the reaction $\mathrm{A}+\mathrm{B} \rightarrow$ product is given by rate $=k[A][B]$ Calculate $[A]$ if rate of reaction and rate constant are $0.25 \mathrm{~mol} \mathrm{dm}^{-3} \mathrm{~s}^{-1}$ and $6.25 \mathrm{~mol}^{-1} \mathrm{dm}^3 \mathrm{~s}^{-1}$ respectively $\left[[\mathrm{B}]=0.25 \mathrm{~mol} \mathrm{dm}^{-3}\right]$
  1. $0.22 \mathrm{~mol} \mathrm{dm}^3$
  2. $0.16 \mathrm{~mol} \mathrm{dm}^3$
  3. $0.30 \mathrm{~mol} \mathrm{dm}^3$
  4. $0.25 \mathrm{~mol} \mathrm{dm}^3$

Solution

$\begin{aligned} \text { rate }=\mathrm{k}[\mathrm{A}][\mathrm{B}] & \\ \therefore \quad[\mathrm{A}]=\frac{\text { rate }}{\mathrm{k}[\mathrm{B}]} & =\frac{0.25 \mathrm{~mol} \mathrm{dm}^{-3} \mathrm{~s}^{-1}}{6.25 \mathrm{~mol}^{-1} \mathrm{dm}^3 \mathrm{~s}^{-1} \times 0.25 \mathrm{~mol} \mathrm{dm}^{-3}} \\ & =0.16 \mathrm{~mol} \mathrm{dm}^3\end{aligned}$

Asked in: MHT CET 2023 (09 May Shift 2)

Practice more Chemical Kinetics questions on Aicharya