Easy MCQ +4 / -1 PYQ · JEE Mains 2025

Consider an elementary reaction

$$ \mathrm{A}(\mathrm{~g})+\mathrm{B}(\mathrm{~g}) \rightarrow \mathrm{C}(\mathrm{~g})+\mathrm{D}(\mathrm{~g}) $$

If the volume of reaction mixture is suddenly reduced to $\frac{1}{3}$ of its initial volume, the reaction rate will become ' $x^{\prime}$ times of the original reaction rate. The value of $x$ is :

  1. A <p>3</p>
  2. B <p>9</p> Correct answer
  3. C <p>$\frac{1}{3}$</p>
  4. D <p>$\frac{1}{9}$</p>

Solution

<p>$$\begin{aligned} & \mathrm{R}_1=\mathrm{K}[\mathrm{~A}]^1[\mathrm{~B}]^1 \\ & \mathrm{R}_1=\mathrm{K}\left[\frac{\mathrm{n}_{\mathrm{A}}}{\mathrm{~V}}\right]^1\left[\frac{\mathrm{n}_{\mathrm{B}}}{\mathrm{~V}}\right]^1 \\ & \mathrm{R}_2=\mathrm{K}\left[\frac{3 \mathrm{n}_{\mathrm{A}}}{\mathrm{~V}}\right]^1\left[\frac{3 \mathrm{n}_{\mathrm{B}}}{\mathrm{~V}}\right]^1 \\ & \mathrm{R}_2=9 \mathrm{R}_1 \end{aligned}$$</p>

About this question

Subject: Chemistry · Chapter: Chemical Kinetics · Topic: Rate of Reaction

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