Question

What is the effect of temperature and concentration on acid disociation constant?

Answer 1

Well, equilibrium constants are generally INDEPENDENT of concentration...

Explanation:

...however, we would expect that for weak acids, `HX`, whose protonolysis reaction we would represent as the equilibrium ...

`HX(aq)+H_2O(l)rightleftharpoonsH_3O^+ + X^-`

Now this is a BOND-BREAKING reaction...i.e. we break the `H-X` bond....and we expect that if we supply heat, we should drive the equilibrium to the right. And so let us look at some data..

`2H_2O(l) rightleftharpoonsH_3O^+ + HO^-` `K_a=10^-14` at `298*K`...

According to this site `pK_a=6.63` at `50` `""^@C`, and `pK_a=6.14` at `100` `""^@C`. Perhaps you could work out values for `K_a` at each temperature. Are these data in accord with our prediction? Why or why not?