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 (Ka= 10-5)

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 (Ka= 10-5) (A) 1:10 (B) 10:1 (C) 100:1 (D) 1:100

Tardigrade Admin · Accepted Answer

pH=pKa+log ( text[Salt]/ text[base]) pKa=-log Ka=-log 10-5=+5 log ( text[Salt]/ text[base])=PH-pKa=6-5=1 ( text[Salt]/ text[base]) =antilog (1) = 10 Thus [Salt]: [base]=10: 1

Q. 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 $(K_{a} = 1 0^{- 5})$

1:10

10:1

100:1

1:100

$p H = p K_{a} + l o g \frac{[Salt]}{[base]}$
$p K_{a} = - l o g K_{a} = - l o g 1 0^{- 5} = + 5$
$l o g \frac{[Salt]}{[base]} = P H - p K_{a} = 6 - 5 = 1$
$\frac{[Salt]}{[base]}$ =antilog $(1) = 10$
Thus $[S a lt] : [ba se] = 10 : 1$

Q. 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 (Ka​=10−5)