Question

Ammonia, NH3 is a common base with Kb of 1.8 X 10-5. For a solution of 0.150 M NH3:

Write the equation for the ionization of ammonia in water.


List all species present in the solution AND determine the concentrations of each.





Determine the pH of this solution.

Answer 1

The concentrations : 0.15 M

pH=11.21

Further explanation

The ionization of ammonia in water :

NH₃+H₂O⇒NH₄OH

NH₃+H₂O⇒NH₄⁺ + OH⁻

The concentrations of all species present in the solution = 0.15 M

Kb=1.8 x 10⁻⁵

M=0.15

`\tt [OH^-]=√(Kb.M)\\\\(OH^-]=\sqrt{1.8* 10^(-5)* 0.15}\\\\(OH^-]=\sqrt{2.7* 10^(-6)}=1.64* 10^(-3)`

`\tt pOH=-log[OH^-]\\\\pOH=3-log~1.64=2.79\\\\pH=14-2.79=11.21`