Question

Arun setup a reaction in a chemistry lab $[2A\to B]$. All the information he have is, it is a second order reaction. Now he wants to increase the rate of reaction to 16 times. He knows that by increasing the concentration, the rate increases, but he doesn’t know, what is the final concentration have to be? Can you help him finding it?

• A. Increase the concentration of A by 2 times.
• B. Increase the concentration of A by 3 times.
• C. Increase the concentration of A by 8 times.
• D. Increase the concentration of A by 4 times.

Answer 1

The correct option is D Increase the concentration of A by 4 times.

Use the Rate Equation $Rate=[Reactant{]}^2$ for second order reaction.

$Rate=[A{]}^2$
$Rate=[4A{]}^2$
$Rate=16[A{]}^2$
Therefore, the rate increases 16 times by increasing the concentration of A by 4 times.