One litre of a buffer solution containing 0.01 M NH 4 Cl and 0.1 M NH 4 OH having p Kb of 5 has pH of

Question

One litre of a buffer solution containing 0.01 M NH 4 Cl and 0.1 M NH 4 OH having p Kb of 5 has pH of (A) 9 (B) 10 (C) 6 (D) 7

Tardigrade Admin · Accepted Answer

Given, conc. of NH 4 OH =0.1 M conc. of NH 4 Cl =0.01 M p Kb=5 ∵ pOH = p Kb+ log ([ text salt ]/[ text base ]) =5+ log (0.01/0.1)=5+ log 10-1 =5-1=4 ∴ pH =14-4=10

Q. One litre of a buffer solution containing $0.01 M N H_{4} Cl$ and $0.1 M N H_{4} O H$ having $p K_{b}$ of $5$ has $p H$ of

9

10

6

7

Given,
conc. of $N H_{4} O H = 0.1 M$
conc. of $N H_{4} Cl = 0.01 M$
$p K_{b} = 5$
$∵ pO H = p K_{b} + lo g \frac{[ salt ]}{[ base ]}$
$= 5 + lo g \frac{0.01}{0.1} = 5 + lo g 1 0^{- 1}$
$= 5 - 1 = 4$
$∴ p H = 14 - 4 = 10$

Q. One litre of a buffer solution containing 0.01MNH4​Cl and 0.1MNH4​OH having pKb​ of 5 has pH of

9

10

6

7

Given, conc. of NH4​OH=0.1M conc. of NH4​Cl=0.01M pKb​=5 ∵pOH=pKb​+log[ base ][ salt ]​ =5+log0.10.01​=5+log10−1 =5−1=4 ∴pH=14−4=10

Q. One litre of a buffer solution containing $0.01 M N H_{4} Cl$ and $0.1 M N H_{4} O H$ having $p K_{b}$ of $5$ has $p H$ of

Given,
conc. of $N H_{4} O H = 0.1 M$
conc. of $N H_{4} Cl = 0.01 M$
$p K_{b} = 5$
$∵ pO H = p K_{b} + lo g \frac{[ salt ]}{[ base ]}$
$= 5 + lo g \frac{0.01}{0.1} = 5 + lo g 1 0^{- 1}$
$= 5 - 1 = 4$
$∴ p H = 14 - 4 = 10$