The pH of a solution of weak base at neutralization with strong acid is 8 . Kb for the base is

Question

The pH of a solution of weak base at neutralization with strong acid is 8 . Kb for the base is (A) 1.0 × 10-4 (B) 1.0 × 10-6 (C) 1.0 × 10-8 (D) None of there

Tardigrade Admin · Accepted Answer

At half neutralization, [ B ⊕]=[ BOH ] ;[ text Salt ]=[ text base ] pOH = p Kb+ log ([ B ⊕]/[ BOH ]) pOH = p Kb,( pH =8, pOH =6) ∴ p Kb=6, Kb=1 × 10-6

Q. The $p H$ of a solution of weak base at neutralization with strong acid is $8. K_{b}$ for the base is

$1.0 \times 1 0^{- 4}$

$1.0 \times 1 0^{- 6}$

$1.0 \times 1 0^{- 8}$

None of there

At half neutralization,
$[B^{\oplus}] = [BO H]; [Salt] = [base]$
$pO H = p K_{b} + lo g \frac{[ B ^{\oplus} ]}{[ BO H ]}$
$pO H = p K_{b}, (p H = 8, pO H = 6)$
$∴ p K_{b} = 6, K_{b} = 1 \times 1 0^{- 6}$

Q. The pH of a solution of weak base at neutralization with strong acid is 8.Kb​ for the base is

1.0×10−4

1.0×10−6

1.0×10−8