Can someone please fully explain the affect of temperature on equilibrium using Le Chatelier's principle? Also, how does kinetic energy of the mc relate to this? Thanks.

1 Answer
Nov 15, 2016

Temperature can have two different effects on a dynamic equilibrium, depending if it's an increase or decrease in temperature.

Explanation:

Consider the following reversible reaction:

#"A " + " B " rightleftharpoons " C " + " D "# #Delta"H"=-250 "kJ"#

When the reaction occurs, #250 " kJ"# of heat energy are given out. And according to Le Chatelier's principle, the system will always work to oppose the changes made to it.

If the temperature is increased, then the backwards reaction will be favoured. During the forwards reaction, heat is produced; thus, during the backwards reaction, heat must be absorbed. Therefore, the equilibrium will shift towards that backwards reaction in order to get rid of the extra heat energy.

The opposite is also true. If the temperature is decreased, then the forwards reaction will be favoured. During the forwards reaction, heat is produced; thus, during the backwards reaction, heat must be absorbed. Therefore, the equilibrium will shift towards that forwards reaction to produce extra heat energy to balance the shift.