If the pKa of acetic acid and pKb of dimethylamine are 4.76 and 3.26 respectively, the pH of dimethyl ammonium acetate solution is

Question

If the pKa of acetic acid and pKb of dimethylamine are 4.76 and 3.26 respectively, the pH of dimethyl ammonium acetate solution is (A) 7.75 (B) 6.75 (C) 7.0 (D) 8.5

Tardigrade Admin · Accepted Answer

pH =7+(1/2)[ p Ka- p Kb] Here, p Ka=4.76, p Kb=3.26 =7+(1/2)[4.76-3.26] =7+(1/2)[1.50] =7+0.75=7.75

Q. If the $p K_{a}$ of acetic acid and $p K_{b}$ of dimethylamine are $4.76$ and $3.26$ respectively, the pH of dimethyl ammonium acetate solution is

7.75

6.75

7.0

8.5

$p H = 7 + \frac{1}{2} [p K_{a} - p K_{b}]$

Here, $p K_{a} = 4.76, p K_{b} = 3.26$

$= 7 + \frac{1}{2} [4.76 - 3.26]$

$= 7 + \frac{1}{2} [1.50]$

$= 7 + 0.75 = 7.75$

Q. If the pKa​ of acetic acid and pKb​ of dimethylamine are 4.76 and 3.26 respectively, the pH of dimethyl ammonium acetate solution is

7.75

6.75

7.0

8.5

pH=7+21​[pKa​−pKb​] Here, pKa​=4.76,pKb​=3.26 =7+21​[4.76−3.26] =7+21​[1.50] =7+0.75=7.75

Q. If the $p K_{a}$ of acetic acid and $p K_{b}$ of dimethylamine are $4.76$ and $3.26$ respectively, the pH of dimethyl ammonium acetate solution is

$p H = 7 + \frac{1}{2} [p K_{a} - p K_{b}]$

Here, $p K_{a} = 4.76, p K_{b} = 3.26$

$= 7 + \frac{1}{2} [4.76 - 3.26]$

$= 7 + \frac{1}{2} [1.50]$

$= 7 + 0.75 = 7.75$