Chemical KineticsmediumMCQ SINGLE

The rate of reaction between two reactants and decreases by a factor of if the concentration of reacChemical Kinetics Chemistry Question

Question

The rate of reaction between two reactants $A$ and $B$ decreases by a factor of $4$ if the concentration of reactant $B$ is doubled (keeping $A$ constant). The order of this reaction with respect to reactant $B$ is:

Answer: B

💡 Solution & Explanation

Let $\text{Rate} = k[A]^x[B]^y$. When $[B]$ is doubled, new rate is $\text{Rate}_{new} = k[A]^x(2[B])^y = 2^y \times \text{Rate}$. Given that the rate decreases by a factor of 4, $\text{Rate}_{new} = \frac{1}{4} \text{Rate}$. So, $2^y = \frac{1}{4} = 2^{-2}$, resulting in $y = -2$.

💬
Still have doubts about this question?
Send it to our AI chemistry tutor on WhatsApp — gets answered in minutes
Ask on WhatsApp →

Practice 22,000+ questions like this

AI-adaptive practice, video lectures, and full NEET Chemistry content — all in one place.

JEE Advanced · JEE Mains · NEET · IChO · AP Chemistry