Calculate the pH of a .7 M solution of ammonium chloride
NH4Cl is a salt and the NH4^+ hydrolyzes.
........NH4^+ + H2O ==> NH3 + H3O^+
initial..0.7.............0.....0
change....-x.............x.....x
equil.....0.7-x..........x.....x
Set up the Ka equation for NH4^+ as
Ka = (Kw/Kb) = (NH3)(H3O^+)/(NH4^+).
You know Kw. Kb is the ionization constant for the base (NH3) which you can find in your text or notes. Solve for x and convert to pH.