Question

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

• A. 10.8 g
• B. 54.0 g
• C. 108.0 g
• D. 5.4 g

Answer 1

The Correct Option is C

To solve this problem, we need to calculate the equivalent weight of silver (Ag) that is displaced by the same quantity of electricity that displaces 5600 mL of oxygen (O₂) at Standard Temperature and Pressure (STP).

First, we determine the amount of electricity passed using the volume of oxygen displaced:

1. At STP, 1 mole of any gas occupies 22.4 L (22400 mL). Therefore, the moles of O₂ displaced by electricity is given by:

\text{Moles of } O_2 = \frac{5600 \text{ mL}}{22400 \text{ mL/mol}} = 0.25 \text{ mol}

2. The reaction for the liberation of oxygen can be represented as:
   2 \text{H}_2\text{O} \rightarrow 2 \text{H}_2 + \text{O}_2
   From the balanced reaction, 4 moles of electrons are required to release 1 mole of O₂.
   Thus, the moles of electrons required to produce 0.25 moles of O₂ is:

0.25 \text{ mol of } O_2 \times 4 \text{ mol of electrons/mol of } O_2 = 1 \text{ mol of electrons}

3. Now, calculate the weight of silver displaced:
   The reaction for the liberation of silver can be represented as:
   \text{Ag}^+ + e^- \rightarrow \text{Ag}
   This implies that 1 mole of electrons will deposit 1 mole of silver atoms.
   Therefore, the mass of silver displaced by 1 mole of electrons is:

\text{Weight of Ag} = 1 \text{ mole} \times 108 \text{ g/mol} = 108 \text{ g}

Hence, the weight of silver displaced by the given quantity of electricity is 108.0 g.