question_answer

                    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? \[(\log \text{ }2.7\text{ }=0.43)\]                                                                                     [AIPMT (S) 2011]

A)  9.43     

B)       11.72  

C)  8.73                

D)       9.08

Correct Answer: A

Solution :