Question

Rates of a reaction are sensitive to temperature. If a slow folding step (like a Pro isomerization) takes 9 minutes but you need to be able to measure it in 60 seconds (because the UV signal gets noisy after that), by how much and in what direction should you vary T if in general reaction rates increase by a factor of 3X for every 10 °C in temperature?

Answer 1

The reaction rates are increased by a factor of 3X for every 10C rise in temperature

Time taken for folding step = 9 minutes = 9 * 60 = 540 seconds

Time in which it must be completed = 60 seconds

Hence the reduction in time factor = 540/60 = 9

For every 10C rise in temperature, the reaction rates increase by a factor of 10

Let the temperature at right now be T K

at (T+10)K, reaction rate will become completing the reaction in 3 minutes

at (T+20)K, reaction rate will become completing the reaction in 1 minute = 60 sec

Hence the temperature must be increased by 20K or 20C in order to complete the reaction in 60 seconds as compared to 9 minutes