Question

The weight of silver (at. wt. = 108) displaced by a quantity of electricity which displaces 5600 mL of O₂ at STP will be ______.

Options

• 5.4 g

• 10.8 g

• 54.0 g

• 108.0 g

Answer 1

The weight of silver (at. wt. = 108) displaced by a quantity of electricity which displaces 5600 mL of O₂ at STP will be 108.0 g.

Explanation:

At STP, 1 mole of O₂ = 22.4 L = 22400 mL and involves 4 Faradays for the reaction.

\[\ce{O2 + 4e- -> 2O^2-}\]

5600 mL O₂ = `5600/22400`

= 0.25 mol O₂

Requires 0.25 × 4 = 1 Faraday

1 Faraday deposits 1 gram equivalent of Ag.

Eq. wt. of Ag = `("At. wt.")/n`

= `108/1`

= 108

But only 1 Faraday is passed, so mass of Ag = 108 × 1 = 108 g