How do I know whether a base is strong or not?

[simphys]

Homework Statement

that is the question.

Relevant Equations

chemistry

So I know that I can get whether an acid is strong or not from a table where if ##pK_a## < 0 than it is a strong acid, but there is no such table for bases, so how do I determine whether a base is strong or weak?

Also.. for metalhydroxides MOH, which will be strong and which are weak bases?
Thanks in advance!

 

[simphys]

or.... do we consider all of the metalhydroxides (that do not hydrolise) to be strong bases because they will form OH- ions which is basically considered a strong base?

 

[Borek]

there is no such table for bases

Sure there are, how do you think I know pKb for ammonia is 4.75?

But you are right that Kb values for metal hydroxides are quite difficult to find. That's because they are not that important - most hydroxides are either very strong bases (alkali metal hydroxides are very strong, alkaline earth metal hydroxides are strong and almost fully dissociated, but poorly soluble) or so insoluble discussing their strength is a moot.