Question

For the hypothetical reaction $2A+3B\to \text{products}$, the rate of disappearance of $A$ is $r_1$ and the rate of appearance of $B$ is $r_2$. These are related as:

• A. $r_1=r_2$
• B. $2r_1=3r_2$
• C. $3r_1=2r_2$
• D. $r_1^2=r_2^3$

Answer 1

The correct option is C $3r_1=2r_2$

The expression for the rate of the reaction is, $r=-\frac{1}{2}\frac{d\left[A\right]}{dt}=-\frac{1}{3}\frac{d\left[B\right]}{dt}.$
But $\frac{d\left[A\right]}{dt}=r_1$ and $\frac{d\left[B\right]}{dt}=r_2.$
Hence, $r=-\frac{1}{2}{r}_1=-\frac{1}{3}{r}_2$ or $3r_1=2r_2.$