Question

calculating mass quick check
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)
○ 108 g/mol + 2 (32 g/mol) = 172 g/mol (172 g/mol) (0.04 mol) = 6.88 g
○ 2 (108 g/mol) + 32 g/mol = 248 g/mol (248 g/mol) (0.02 mol) = 4.96 g
○ 2 (108 g/mol) + 32 g/mol = 248 g/mol (248 g/mol) (0.04 mol) = 9.92 g
○ 108 g/mol + 2 (32 g/mol) = 172 g/mol (172 g/mol) (0.02 mol) = 3.44 g

Explanation:

Step1: Calculate molar mass of \(Ag_2S\)

Molar mass of \(Ag_2S=2\times108 + 32=248\space g/mol\)

Step2: Find moles of \(Ag_2S\) from moles of \(Ag\)

From the equation \(2Ag(s)+H_2S(g)\to Ag_2S(s)+H_2(g)\), mole ratio of \(Ag\) to \(Ag_2S\) is \(2:1\). If \(n(Ag) = 0.04\space mol\), then \(n(Ag_2S)=\frac{0.04}{2}=0.02\space mol\)

Step3: Calculate mass of \(Ag_2S\)

\(m(Ag_2S)=n\times M = 0.02\times248 = 4.96\space g\)

Answer:

\(2(108\space g/mol)+32\space g/mol = 248\space g/mol\), \((248\space g/mol)(0.02\space mol)=4.96\space g\)