What are double salts?

What are acid salts? Can you convert an acid salt into a normal salt?

What are neutral salts, acidic salts and basic salts. Give two examples each of neutral, acidic and basic salts.

What is the difference between a complex and a double salt ?

Which of the following pair contains complex salt and double salt respectively?

Both double salt as well as complexes are formed by combination of two or more stable compounds in stoichiometric ratio.However, they differ in the fact that double salt dissociate into simple ions completely when dissolved in water but in complex salt, complex ions doesn't dissociate into ions. Which of the following correct about alums ?