Hi,

Question

I am stuck on this question and would appreciate some guidance. The question states " The value of Kw decreases as the temperature decreases. Is the auto-ionization of water an exothermic or endothermic reaction in the forward direction?"
I feel like the answer should be exothermic as I know from studying Le Chatelier's principle that a decrease in temperature favours the reaction to occur in the forward direction. Is that a correct assumption?

Answer 1

ionization decreases as temp decreases so..
ionization increases as temp increases
water+heat>>ions

endothermic

Answer 2

ionization decreases as temp decreases so..
ionization increases as temp increases
water+heat>>ions

endothermic, so decrease in temp favors reverse.

check my logic

Answer 3

when temp decreases, water will decrease in solubility or in ionization and the reaction will favour the backward reaction;

H+ + OH- --> H2O

so we know that the backward reaction is endothermic and the forward is exothermic.