The rate of a standard reaction is 0.01840 M/s at 25 oC. It is determined that this is too fast, and that the rate should be reduced to 0.0046 M/s.

Question

What temperature should the reaction be run at to achieve this?

A. 45 °C

B. 20 °C

C. 15 °C

D. 5 °C

E. 0 °C

I got D. 5 °C. Would this be correct?

Answer 1

As a rough approximation, the rate of a reaction will double or half for every 10º change in temperature. In this particular case, you want to cut the reaction rate to 1/4 the original. So, yes, running it at around 5º would accomplish this (25º to 15º would ~ halve the rate; 15º to 5º would ~ halve it again).