If the ( pH ) of a buffer solution containing (0.1 M ) of monoacidic base and (0.01 M ) of its salt is 10.5 , the ( p K_a ) of conjugate acid is

Step-by-step solution

Key Idea From Henderson-Hesselbalch equation (p H= p K_a+ [ salt] [acid] ) ( pH ) of a buffer solution (=10.5 ) ( p K_a ) of this buffer solution can be calculated as: ( aligned 10.5 & = p K_a+ [0.01] [0.1] 10.5 & = p K_a+ 10⁻¹ 10.5 & = p K_a-1 p K_a & =11.5 aligned )