Question

The pH of a buffer containing equal molarconcentration of a weak base and its chloride ( $K_b$ for weak base = $2 \times 10^{-5}$, log 2 = 0.3) is

• A. 5
• B. 9
• C. 4.7
• D. 9.3

Answer 1

Answer: (D)

9.3

Answer 2

$pOH=pK_{b}=-log(2\times 10^{-5})=5-0.36=4.70$
Hence $pH=14-4.7=9.3$