At STP, the molar volume of an ideal gas is $22400 \text{ mL/mol}$. Moles of $\text{O}_2$ displaced = $\frac{5600 \text{ mL}}{22400 \text{ mL/mol}} = 0.25 \text{ mol}$.

The half-reaction for the liberation of $\text{O}_2$ is: $2\text{H}_2\text{O} \rightarrow \text{O}_2 + 4\text{H}^+ + 4e^-$ This shows that $1 \text{ mole}$ of $\text{O}_2$ gas is produced by the passage of $4 \text{ moles}$ of electrons ($4 \text{ Faradays}$). Therefore, the charge ($Q$) required to displace $0.25 \text{ moles}$ of $\text{O}_2 = 0.25 \times 4 = 1 \text{ Faraday}$.

The half-reaction for the deposition of silver is: $\text{Ag}^+ + e^- \rightarrow \text{Ag}$ This shows that $1 \text{ Faraday}$ of electricity deposits $1 \text{ mole}$ of $\text{Ag}$. Mass of $1 \text{ mole}$ of $\text{Ag} = 108 \text{ g}$.

Thus, the weight of silver displaced by $1 \text{ Faraday}$ of electricity is $108.0 \text{ g}$.