Use this information: 4 Ag(s)+2 H2S(g) + O2(g) --> 2 Ag2S(s) +2 H2O(l)

Question

What is the mole ratio of H2S(g) to Ag2(s)
A. 2/1
B. 2/2
C. 2/4
D. 4/2

Answer 1

I don't see an Ag2. You must mean Ag2S(s)
Look at the coefficients. So you want (H2S)/(Ag2S). That will be
2H2S
-------- = 2/2 = 1/1
2Ag2S
Technically I was always taught to reduce fractions to their lowest value; therefore I would count 2/2 wrong but that's the only answer that fits. 1/1 is the correct answer.