Silver, when exposed to air, tarnishes. The following reactions have been proposed for this tarnishing: 

The following data are available: 

Air can be assumed to contain 0.5 ppm H₂, 0.03 ppm (80 mg/m³) SO₂, and 0.1 H₂S mg/m³ and water at a partial pressure of 2.0 kPa. 

Which of these reactions are likely to occur at normal conditions and result in the tarnishing of silver?

Transcribed Image Text:

2Ag + O2 → Ag2O 2Ag + H₂S → Ag2S + H₂ 2Ag + H₂O → Ag20 + H₂ 2Ag + SO₂ → Ag2S + O₂