3H2S + K2Cr2O7 + 4H2SO4 → 3S + Cr2(SO4)3 + K2SO3 + 7H2O
Hydrogen sulfide react with potassium dichromate and sulfuric acid to produce sulfur, chromium(III) sulfate, potassium sulfate and water. Hydrogen sulfide - saturated solution. Sulfuric acid - diluted solution.