A buffer solution is prepared in which the concentration of \[N{{H}_{3}}\] is 0.30 M and the concentration of \[NH_{4}^{+}\] is 0.20 M. If the equilibrium constant, \[{{K}_{b}}\] for \[N{{H}_{3}}\] equals \[1.8\times {{10}^{-5}},\]what is the pH of this solution? (log 2.7 = 0.43)