[maccha]

Take for example the hydrolysis of NaF.

Na doesn't react with water but F does according to the equilibrium equation:

H20 + F- <---> HF + OH-

So a basic solution is said to be formed. What I don't understand is that, isn't HF a stronger acid than F- is a base? Wouldn't the solution therefore end up being acidic?

[UG]

HF is actually quite a weak acid in the scheme of things (if you want to know why  http://www.chemguide.co.uk/inorganic/group7/acidityhx.html), the OH^- is the basic part which makes the solution basic.

[Borek]

Strengths of both acid and conugate base are related.

http://www.chembuddy.com/?left=pH-calculation&right=bronsted-lowry-theory

This is a delicate equilibrium, that requires presence of both HF and F^-. If you start with HF only, it will dissociate producing H⁺ and F^- and you will end with acidic solution. If you start with F^- only it will react with water producing OH^- and HF and you will end with basic solution. Pay special attention to this only part of above statements.