Which of the following aqueous solutions will have a $pH$ less than $7.0$?

The aqueous solution of ammonium chloride is

Which of the following dissolves in water to give a neutral solution?

The hydrolysis constant of $0.1 \ M$ ammonium chloride is $2.5 \times 10^{-10}$. Its degree of hydrolysis is......

Which of the following relations is correct for a solution of $CH_3COONH_4$ salt? Concentration $0.001 \ M$,degree of hydrolysis $x_1$; Concentration $0.002 \ M$,degree of hydrolysis $x_2$.

$A$ solution of sodium chloride in contact with the atmosphere has a $pH$ of about