What is the pH of a 0.25 M methylamine solution?

The formula is ch3nh2

so what I did was .25*2=.5

-log(.5)=.30

Calculate the pH of a 0.50 M solution of potassium cyanide

the formula is kcn

I did -log(.5)=.30

Am I doing this right? I feel that since these aren't strong acids/bases there should be more work involved