Question

For preparing a buffer solution of pH 6 by mixing sodium acetate and acetic acid, the ratio of the concentration of salt and acid should be $(K_a= 10^{-5})$

• A. 0.048611111
• B. 10:01
• C. 100:01:00
• D. 0.111111111

Answer 1

Answer: (B)

10:01

Answer 2

$pH=pK_{a}+log \frac{\text{[Salt]}}{\text{[base]}}$ $pK_{a}=-log \, K_{a}=-log\,10^{-5}=+5$ $log \frac{\text{[Salt]}}{\text{[base]}}=PH-pK_{a}=6-5=1$ $\frac{\text{[Salt]}}{\text{[base]}}$ =antilog $(1) = 10$ Thus $[Salt]: [base]=10 : 1$