The degree of hydrolysis of which salt is independent of the concentration of the salt solution?

$A$ weak acid $HX$ $(K_a = 10^{-5})$ on reaction with $NaOH$ gives $NaX$. For $0.1 \ M$ aqueous solution of $NaX$,the $\%$ hydrolysis is $....... \ \%$.

The number of hydroxide ions,produced by one molecule of sodium carbonate $(Na_2CO_3)$ on hydrolysis is

An aqueous solution of $K_2SO_4$ will be ....

$A$ solution of sodium borate has a $pH$ of approximately

Which of the following salts does not undergo hydrolysis in water?