Step-by-step explanation:
We have to put out the balanced chemical equation before proceeding. The equation for the dissociation of sodium sulfide in water is given as;
Na₂S --> 2Na⁺ + S²⁻
From the stoichiometry of the reaction we can tell that;
1 mol of Na₂S produces 2 moles of Na⁺ and 1 mol of S²⁻.
Sodium ion:
1 mol of Na₂S = 2 mol of Na⁺
2,05 = x
upon solving for x;
x = 2 * 2.05 = 4.10 moles
Sulfide ion:
1 mol of Na₂S = 1 mol of S²⁻
2.05 = x
upon solving for x;
x = 1 * 2.05 = 2.05 moles