Question

Observe the following reaction:
$A\left(g\right)+3B\left(g\right)⟶2C\left(g\right)$
The rate of this reaction $\left\{\frac{-d\left[A\right]}{dt}\right\}$ is $3\times {10}^{-3}$ $mol$ ${litre}^{-1}$ ${min}^{-1}$.
What is the value of $\frac{-d\left[B\right]}{dt}$ in $mol$ ${litre}^{-1}$ ${min}^{-1}$?

• A. $3\times {10}^{-3}$
• B. $9\times {10}^{-3}$
• C. ${10}^{-3}$
• D. $1.5\times {10}^{-3}$

Answer 1

The correct option is B $9\times {10}^{-3}$

$-\frac{d\left[A\right]}{dt}=\frac{-1}{3}\frac{d\left[B\right]}{dt}\frac{d\left[B\right]}{dt}=3.\frac{d\left[A\right]}{dt}=9\times {10}^{-3}mol{L}^{-1}mi{n}^{-1}$