K a for butyric acid ( C 3 H 7 COOH ) is 2 × 10-5. The pH of 0.2 M solution of butyric acid is × 10-1. (Nearest integer) [Given log 2=0.30 ]

Question

K a for butyric acid ( C 3 H 7 COOH ) is 2 × 10-5. The pH of 0.2 M solution of butyric acid is × 10-1. (Nearest integer) [Given log 2=0.30 ] (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

K a of Butyric acid ⇒ 2 × 10-5 PKa =4.7 pH of 0.2 M solution pH =(1/2) pK a -(1/2) log C =(1/2)(4 ⋅ 7) (1/2) log (0.2) =2.35+0.35=2.7 pH =27 × 10-1

Q. $K_{a}$ for butyric acid $(C_{3} H_{7} COO H)$ is $2 \times 1 0^{- 5}$ . The $p H$ of $0.2 M$ solution of butyric acid is ___ $\times 1 0^{- 1}$ . (Nearest integer) [Given $lo g 2 = 0.30$ ]

$K_{a}$ of Butyric acid $\Rightarrow 2 \times 1 0^{- 5} P K a = 4.7$
$p H$ of $0.2 M$ solution
$p H = \frac{1}{2} p K_{a} - \frac{1}{2} lo g C$
$= \frac{1}{2} (4 \cdot 7) \frac{1}{2} lo g (0.2)$
$= 2.35 + 0.35 = 2.7$
$p H = 27 \times 1 0^{- 1}$

Q. Ka​ for butyric acid (C3​H7​COOH) is 2×10−5. The pH of 0.2M solution of butyric acid is ___×10−1. (Nearest integer) [Given log2=0.30 ]

Ka​ of Butyric acid ⇒2×10−5PKa=4.7 pH of 0.2M solution pH=21​pKa​−21​logC =21​(4⋅7)21​log(0.2) =2.35+0.35=2.7 pH=27×10−1

Q. $K_{a}$ for butyric acid $(C_{3} H_{7} COO H)$ is $2 \times 1 0^{- 5}$ . The $p H$ of $0.2 M$ solution of butyric acid is ___ $\times 1 0^{- 1}$ . (Nearest integer) [Given $lo g 2 = 0.30$ ]

$K_{a}$ of Butyric acid $\Rightarrow 2 \times 1 0^{- 5} P K a = 4.7$
$p H$ of $0.2 M$ solution
$p H = \frac{1}{2} p K_{a} - \frac{1}{2} lo g C$
$= \frac{1}{2} (4 \cdot 7) \frac{1}{2} lo g (0.2)$
$= 2.35 + 0.35 = 2.7$
$p H = 27 \times 1 0^{- 1}$