Question

For the reaction : $aA+bB\to cC+dD$
Rate $=\frac{dx}{dt}=\frac{-1}{a}\frac{d\left[A\right]}{dt}=\frac{-1}{b}\frac{d\left[B\right]}{dt}=\frac{-1}{c}\frac{d\left[C\right]}{dt}=\frac{-1}{d}\frac{d\left[D\right]}{dt}$

For reaction $3Br{O}^{\ominus }\to Br{O}_3^{\ominus }+2B{r}^{\ominus }$, the value of rate constant at ${80}^{\circ }C$ in the rate for $-\frac{-d\left[Br{O}^{\ominus }\right]}{dt}$ was found to be $0.054Lmo{l}^{-1}{s}^{-1}$. The rate constant (k) for the reaction in terms of $\frac{d\left[Br{O}_3^{\ominus }\right]}{dt}$ is :

• A. $0.018Lmo{l}^{-1}{s}^{-1}$
• B. $0.162Lmo{l}^{-1}{s}^{-1}$
• C. $0.036Lmo{l}^{-1}{s}^{-1}$
• D. none

Answer 1

The correct option is A $0.018Lmo{l}^{-1}{s}^{-1}$

For the given reaction
$\frac{1}{3}\frac{-d\left[Br{O}^{\ominus }\right]}{dt}=\frac{d\left[Br{O}_3^{\ominus }\right]}{dt}=\frac{1}{2}\frac{d\left[Br\right]}{dt}$
Since, rate $\propto$ rate constant
$\therefore \frac{d\left[Br{O}_3^{\ominus }\right]}{dt}=\frac{1}{3}\times 0.054=0.018Lmo{l}^{-1}{s}^{-1}$