A student constructs a galvanic cell at \(298\text{ K}\) based on the following overall reaction:

\[ \text{Zn}(s) + \text{Cu}^{2+}(aq) \rightarrow \text{Zn}^{2+}(aq) + \text{Cu}(s) \quad E^\circ_{\text{cell}} = +1.10\text{ V} \]

Initially, both half-cells contain \(1.0\text{ M}\) aqueous solutions. The student then adds a small amount of solid sodium sulfide, \(\text{Na}_2\text{S}(s)\), to the anode compartment, which causes a precipitate of \(\text{ZnS}(s)\) to form without significantly changing the volume of the solution.

Which of the following best predicts and justifies the effect of adding \(\text{Na}_2\text{S}(s)\) on the cell potential, \(E_{\text{cell}}\)?