Question

a)predict whether a 2.0mol/L solution of ammonia chloride will be acidic basic or neutral

b) calculate the pH of a 0.20 mil/L solution of NH4Cl

Answer 1

You know it will be acidic because it hydrolyzes to give H3O^+.
Part a is a 2.0 M solution; part b is a 0.2 M solution.
....................NH4^+ + HOH ==> NH3 + H3O^+
I....................0.2M........................0............0
C......................-x..........................x............x
E...................0.2-x.........................x............x

Ka for NH4^+ = Kw/Kb for NH3 = (NH4^+)(H3O^+)/(NH4^+)
Plug the E line into the Ka expression and solve for H3O^+, then convert to pH. You should get in the neighborhood of 5 for the pH.