Silver tarnishes when exposed to oxygen and dihydrogen monosulfide. The chemical
reaction is as follows:
4Ag (s) + 2H₂S (g) + O₂ → 2Ag₂S (s) + 2H₂O (1)
tarnish
silver
Every household has some H₂S in the air (it smells like rotting eggs), but there is usually
only a small quantity. H₂S is almost always the limiting reactant in this reaction. If a silver
spoon has 0.0030 moles of tarnish on it, how many moles of H₂S was it exposed to?
