Question

For the reaction $A\left(g\right)+3B\left(g\right)\to 2C\left(g\right),$
What will be the ratio of rate of formation of $C\left(g\right)$ to rate of consumption of $A\left(g\right)$?

• A. $1:3$
• B. $3:1$
• C. $1:2$
• D. $2:1$

Answer 1

The correct option is D $2:1$

For
$A\left(g\right)+3B\left(g\right)\to 2C\left(g\right)$
$\text{Overall rate}\left(r\right)=-1\times \frac{d\left[A\right]}{dt}=-\frac{1}{3}\times \frac{d\left[B\right]}{dt}=+\frac{1}{2}\times \frac{d\left[C\right]}{dt}$

$\Rightarrow -1\times \frac{d\left[A\right]}{dt}=+\frac{1}{2}\times \frac{d\left[C\right]}{dt}$

$-\frac{d\left[A\right]}{dt}=\text{rate of consumption of}A$

$+\frac{d\left[C\right]}{dt}=\text{rate of formation of}C$

$\frac{\text{Rate of formation of}C}{\text{Rate of consumption of}A}=\frac{+\frac{d\left[C\right]}{dt}}{-\frac{d\left[A\right]}{dt}}=\frac{2}{1}\text{Desired Ratio}=2:1$