If the pH of a mixture of 10 mL of 0.1 M NH4OH and 10 mL of 1 M NH4Cl solution is 8, the pKb value of NH4OH is the n closest to

Question

If the pH of a mixture of 10 mL of 0.1 M NH4OH and 10 mL of 1 M NH4Cl solution is 8, the pKb value of NH4OH is the n closest to (A) 3 (B) 5 (C) 7 (D) 9

Tardigrade Admin · Accepted Answer

Given, pH of a mixture = 8 Concentration of NH4OH = 0.1 M Concentration of NH4 Cl = 1 M pOH = 14 - pH pOH=14-8=6 ∴ PKb=pOH+ log([NH4Cl]/[NH4OH]) 6+ log([1]/[0.1]) =6+ log 10 =6+1=7

Q. If the $p H$ of a mixture of $10 m L$ of $0.1 M N H_{4} O H$ and $10 m L$ of $1 M N H_{4} Cl$ solution is $8$ , the $p K_{b}$ value of $N H_{4} O H$ is the n closest to

3

5

7

9

Given, $p H$ of a mixture = $8$
Concentration of $N H_{4} O H = 0.1 M$
Concentration of $N H_{4} Cl = 1 M$
$pO H = 14 - p H$
$pO H = 14 - 8 = 6$
$∴ P K_{b} = pO H + lo g \frac{[ N H _{4} Cl ]}{[ N H _{4} O H ]}$
$6 + lo g \frac{[ 1 ]}{[ 0.1 ]}$
$= 6 + lo g 10$
$= 6 + 1 = 7$

Q. If the pH of a mixture of 10mL of 0.1MNH4​OH and 10mL of 1MNH4​Cl solution is 8, the pKb​ value of NH4​OH is the n closest to

3

5

7

9

Given, pH of a mixture = 8 Concentration of NH4​OH=0.1M Concentration of NH4​Cl=1M pOH=14−pH pOH=14−8=6 ∴PKb​=pOH+log[NH4​OH][NH4​Cl]​ 6+log[0.1][1]​ =6+log10 =6+1=7

Q. If the $p H$ of a mixture of $10 m L$ of $0.1 M N H_{4} O H$ and $10 m L$ of $1 M N H_{4} Cl$ solution is $8$ , the $p K_{b}$ value of $N H_{4} O H$ is the n closest to

Given, $p H$ of a mixture = $8$
Concentration of $N H_{4} O H = 0.1 M$
Concentration of $N H_{4} Cl = 1 M$
$pO H = 14 - p H$
$pO H = 14 - 8 = 6$
$∴ P K_{b} = pO H + lo g \frac{[ N H _{4} Cl ]}{[ N H _{4} O H ]}$
$6 + lo g \frac{[ 1 ]}{[ 0.1 ]}$
$= 6 + lo g 10$
$= 6 + 1 = 7$