Question

__ AgI + __ Na2S → __ Ag2S + __ NaI

Answer 1

2 AgI + Na2S = Ag2S + 2 NaI

Answer 2

The balanced chemical equation for the given reaction is

$2AgI + Na_{2}S$→ $Ag_{2}S + 2NaI$.

• Silver Iodide reacts with sodium sulfide to form silver sulfide and sodium iodide.
• The silver sulfide is insoluble in water and forms a dense black precipitate.
• The given reaction is a double displacement reaction where the ions in the reactants are interchanged.
• The chemical reaction must be balanced, that is, the number of moles of elements on both sides must be equal.
• As the product Silver sulfide has two Ag, on the reactant side also there must be two. So two moles of silver iodide are involved in the reaction.
• Similarly, the reactant sodium sulfide has two Sodium atoms, so there must be two on the product side also. So two moles of sodium iodide must be formed in the reaction.
• Hence, two moles of silver iodide react with a mole of sodium sulfide to form a mole of silver sulfide and two moles of sodium iodide.