For the reaction $2 \mathrm{NOBr}_{(\mathrm{g})} \rightarrow 2 \mathrm{NO}_{(\mathrm{g})}+\mathrm{Br}_{…

For the reaction $2 \mathrm{NOBr}_{(\mathrm{g})} \rightarrow 2 \mathrm{NO}_{(\mathrm{g})}+\mathrm{Br}_{ \left.2_{(\mathrm{g})}\right)}$, rate law is $\mathrm{r}=\mathrm{K}[\mathrm{NOBr}]^{2}$ If rate constant is $1 \cdot 62 \mathrm{M}^{-1} \mathrm{~s}^{-1}$ and concentration of $\mathrm{NOBr}$ is $2 \cdot 00 \times 10^{-3} \mathrm{M}$, What is the rate of reaction?
  1. $6 \cdot 48 \times 10^{-6} \mathrm{Ms}^{-1}$
  2. $4 \cdot 05 \times 10^{-5} \mathrm{Ms}^{-1}$
  3. $2 \cdot 46 \times 10^{-6} \mathrm{Ms}^{-1}$
  4. $5 \cdot 24 \times 10^{-6} \mathrm{Ms}^{-1}$

Solution

$2 \mathrm{NOBr}_{(\mathrm{g})} \rightarrow 2 \mathrm{NO}_{(\mathrm{g})}+\mathrm{Br}_{2(\mathrm{~g})}$, $\mathrm{k}=1.62 \mathrm{~M}^{-1} \mathrm{~s}^{-1},[\mathrm{NOBr}]=2.00 \times 10^{-3} \mathrm{~M}$ Now, $\mathrm{r}=\mathrm{k}[\mathrm{NOBr}]^{2}$ $\therefore \mathrm{r}=1.62 \mathrm{~M}^{-1} \mathrm{~s}^{-1} \times\left(2.00 \times 10^{-3}\right)^{2} \mathrm{M}^{2}$ $\therefore \mathrm{r}=6.48 \times 10^{-6} \mathrm{~M} \mathrm{~s}^{-1}$

Asked in: MHT CET 2020 (20 Oct Shift 2)

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