Question

Use the chemical equation to answer the question.

2Ag(s) + H2S(g) → Ag2S(s) + H2(g)

The molar mass of silver (Ag) is 108 g/mol. The molar mass of sulfur (S) is 32 g/mol. The reaction uses 0.04 mol of silver. Which steps show how to determine the mass of silver sulfide (Ag2S) produced in the reaction?

(1 point)
Responses

1.) 108 g/mol+2(32 g/mol)=172 g/mol


2.) 2(108 g/mol)+32 g/mol=248 g/mol


3.) 108 g/mol+2(32 g/mol)=172 g/mol


4.) 2(108 g/mol)+32 g/mol=248 g/mol

Answer 1

Use the stoichiometry and molar mass:

1) Molar mass Ag2S = 2(108) + 32 = 248 g/mol. (this is response 2 or 4)
2) Moles Ag2S produced = 0.04 mol Ag × (1 mol Ag2S / 2 mol Ag) = 0.02 mol Ag2S.
3) Mass Ag2S = 0.02 mol × 248 g/mol = 4.96 g (≈ 5.0 g).

So pick response 2 (or 4); the mass produced is 4.96 g.