Q25 / 150 · MHT CET 2026 (16 April Shift 2) · Chemistry
What mass of silver (Atomic mass = 108 g/mol) deposited by a quantity of electricity which displaces 5600 mL of $\text{O}_2$ at STP ?
- A$5.4\ \text{g}$
- B$10.8\ \text{g}$
- C$54.0\ \text{g}$
- Correct answerD$108.0\ \text{g}$
Solution
Volume of $O_2$ displaced at STP = $5600$ mL = $5.6$ L.
Moles of $O_2$ = $\dfrac{5.6}{22.4} = 0.25$ mol.
The reaction for the liberation of $O_2$ is:
$2H_2O \rightarrow O_2 + 4H^+ + 4e^-$
Number of moles of electrons (Faradays) required for $0.25$ mol of $O_2$ = $0.25 \times 4 = 1$ F.
The reaction for the deposition of silver is:
$Ag^+ + e^- \rightarrow Ag$
Since $1$ F of electricity deposits $1$ mole of Ag, the mass of Ag deposited is:
$1 \times 108 = 108.0$ g.
Answer: $108.0\ \text{g}$
Moles of $O_2$ = $\dfrac{5.6}{22.4} = 0.25$ mol.
The reaction for the liberation of $O_2$ is:
$2H_2O \rightarrow O_2 + 4H^+ + 4e^-$
Number of moles of electrons (Faradays) required for $0.25$ mol of $O_2$ = $0.25 \times 4 = 1$ F.
The reaction for the deposition of silver is:
$Ag^+ + e^- \rightarrow Ag$
Since $1$ F of electricity deposits $1$ mole of Ag, the mass of Ag deposited is:
$1 \times 108 = 108.0$ g.
Answer: $108.0\ \text{g}$
Hence, the correct answer is option: 'D'.