Aqueous solution of ferric chloride is

Solutions of equal concentration of the following substances are prepared separately. Which of these solutions will have the minimum $pH$?

Which of the following aqueous salt solutions has the least $pH$ value?

An aqueous solution of $Al_2(SO_4)_3$ is .......

Which of the following aqueous solutions of salts will have the highest $pH$ value?

The degree of hydrolysis of a salt of weak acid and weak base in its $0.1 \, M$ solution is found to be $50 \%$. If the molarity of the solution is $0.2 \, M$,the percentage hydrolysis of the salt should be $...... \%$.