I recently stumbled upon a question that I didn't really understand how to answer.

For a 0.20 M solution of potassium sulfate, K_{2}SO_{4}, calculate the amount, in mol, of:

a) Potassium ions, K^{+}

b) Sulfate ions, SO_{4}^{2-}

c)Oxygen atoms

I first thought that you would need to do n=C x V but with no Volume given i was unsure of how to answer it

I did decide to convert 0.20M/0.20mol L^{-1} into g L^{-1} = 0.20M x 174gMol^{-1} which gave a result of 34.86 g L^{-1}. This is where i am stuck, I don't know what do do from here =/ Any help is good.

Thanks again, appreciate all the effort.