A solution of NaOH contain 0.04 gm of NaOH per litre. Its pH is

Question

A solution of NaOH contain 0.04 gm of NaOH per litre. Its pH is (A) 10 (B) 9 (C) 11 (D) 12

Tardigrade Admin · Accepted Answer

0.04 g of NaOH ⇒ (0.04 g/40 g mol-1)=10-3 moles of NaOH <img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/chemistry/a327c94cbff5ac9cef94f8c30538b6d8-.png" /> ∴ [ OH -]=10-3 ⇒ p [ OH ]=3 ⇒ pH =14-3=11

Q. A solution of $N a O H$ contain $0.04 g m$ of $N a O H$ per litre. Its $p H$ is

10

9

11

12

$0.04 g$ of $N a O H$
$\Rightarrow \frac{0.04 g}{40 g m o l ^{- 1}} = 1 0^{- 3}$ moles of $N a O H$

$∴ [O H^{-}] = 1 0^{- 3}$
$\Rightarrow p [O H] = 3$
$\Rightarrow p H = 14 - 3 = 11$

Q. A solution of NaOH contain 0.04gm of NaOH per litre. Its pH is

10

9

11

12

0.04g of NaOH ⇒40gmol−10.04g​=10−3 moles of NaOH ∴[OH−]=10−3 ⇒p[OH]=3 ⇒pH=14−3=11

Q. A solution of $N a O H$ contain $0.04 g m$ of $N a O H$ per litre. Its $p H$ is

$0.04 g$ of $N a O H$
$\Rightarrow \frac{0.04 g}{40 g m o l ^{- 1}} = 1 0^{- 3}$ moles of $N a O H$

$∴ [O H^{-}] = 1 0^{- 3}$
$\Rightarrow p [O H] = 3$
$\Rightarrow p H = 14 - 3 = 11$