tell whether .1M solutions of the following salts would be acidic, neutral, or basic: CaCl2, CuSO4, (NH4)2SO4, KClO4, KClO4, NaCN.

Answer 1

I do these by reasoning. The equations I write are not right but the answers are right.
KClO4 + HOH ==> HClO4 + KOH
HClO4 is a strong acid. KOH is a strong base Therefore, the solution of the salt is neutral.
If the acid is strong and base is weak the solution of the salt will be acidic.
If the acid is weak and base is strong the solution of the salt will be basic.
If the acid is weak and base is weak the salt depends upon which is the stronger of the acid/base combination.