Question

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

Since this is a second order reaction, when you increase the concentration to 4 times its initial amount, the rate increases by $4^2$ times, i.e. 16 times.

Remember rate $\propto [conc{]}^{order}$