I have been plagued by this question for a good half an hour, whilst doing past papers I came across it-

' EXPLAIN why the value of Kw increases as the temperature increases'
as far as I can tell, it is about the excess production of OH- and H+ from le chateliers principle, i feel like it has got to be something to do with exothermic and endothermic favourable directions but I just cant seem to get my head around it.
help would be much appreciated

breaking apart covalent bonds, as in H2O, requires energy. The more energy, the more OH and H+.

Yes, the reaction making more ions is endothermic...it takes energy.

OHHH... so, if more heat energy is provided, then more H2O molecules can be broken to their constituent of OH- and H+ due to the endothermic nature of the reaction, and hence the equilibria would favor to the right hand side of the equation in order to 'use up' the excess heat energy and regain the regular temperature and apposing the change, and hence Kw would increase.

I think I understand now if this is so, thank you for your assistance.

Certainly! The value of Kw, also known as the ion product of water, represents the concentration of hydroxide ions (OH-) multiplied by the concentration of hydronium ions (H+) in water at a specific temperature. The equation for Kw is: Kw = [OH-][H+].

Now, let's analyze why the value of Kw increases as the temperature increases:

1. Shift in equilibrium: At any given temperature, water undergoes auto-ionization, where a small fraction of water molecules dissociate into hydroxide and hydronium ions. This process is reversible, meaning that the hydroxide and hydronium ions can also recombine to form water molecules. This equilibrium is governed by the law of chemical equilibrium, and the concentrations of hydroxide and hydronium ions are related to Kw.

2. Change in reaction rates with temperature: The auto-ionization of water is an example of an endothermic reaction, meaning it requires heat energy to take place. As the temperature increases, the reaction rates of both production and recombination of hydroxide and hydronium ions increase. This is because higher temperatures provide more energy for particles to collide and react.

3. Le Châtelier's principle: According to Le Châtelier's principle, if a system at equilibrium is subjected to a change, the system will try to counteract that change and reestablish equilibrium. In this case, increasing the temperature is a change that favors the endothermic direction of auto-ionization, leading to the production of more hydroxide and hydronium ions.

4. Increase in ion concentrations: As the temperature increases, more hydroxide and hydronium ions are produced relative to their recombination. This leads to an increase in their respective concentrations, resulting in a higher value of Kw.

In conclusion, the increase in temperature favors the endothermic direction of the auto-ionization of water, promoting the production of more hydroxide and hydronium ions. Consequently, the value of Kw, which is the product of their concentrations, increases.