Answer to Question #141687 in General Chemistry for Yuki

Question

Explaining how to produce a temperature jump on the microsecond timescale by the Joule-heating method.

Answer 1

The conducting solution to be used is rapidly perturbed by a rapid change in temperature by the Joule heating device. This is caused by the discharge of a high voltage capacitor through the solution. 

This discharge produces temperature jumps of up to 5°C in as little as 1 to 2µs and causes a new equilibrium constant at the higher temperature. 

However, the initial concentrations are balanced for the lower temperature and the system therefore relaxes until the concentrations have reached their new equilibrium values.

Note that the temperature increase in the conducting solution results

from the resistance to an electric current flowing through it. 

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