Question

For the reaction: $2HI\to H_2+I_2.$ the expression $\frac{-1}{2}\frac{d\left(HI\right)}{dt}$ represents:

• A. the rate of formation of $HI$
• B. the rate of disappearance of $HI$
• C. the instantaneous rate of the reaction
• D. the average rate of reaction

Answer 1

Answer: (C)

the instantaneous rate of the reaction

For the reaction: $2HI\to H_2+I_2$, the expression $\frac{-d\left(HI\right)}{2dt}$ represents the instantaneous rate of the reaction.

The instantaneous rate of the reaction $=\frac{-d\left(HI\right)}{2dt}=\frac{d\left(H_2\right)}{dt}=\frac{d\left(I_2\right)}{dt}$