The equation K2O2 + H2S -> 2KOH + S

In the above equation, K₂O₂ is Potassium peroxide, a pale yellow or opaque white solid. K₂O₂ exists in nature in the form of evenly distributed minerals and is rarely used in industry.
H₂S is Hydrogen sulfide, a white gas, colorless, with a characteristic foul odor.
The right-side products include KOH – Potassium hydroxide also known as caustic potash, and S is sulfur.

Reaction conditions:
- For the reaction to occur, sufficient temperature and pressure are needed. As H₂S is a gas, a high enough pressure condition is needed.
- In addition, the reaction also requires an environment without oxygen to avoid the oxidation of the reactants.
Reaction Process:
- K₂O₂ (s) + H₂S(g) -> 2KOH(s) + S(s)
- The reaction process takes place in the direction of creating KOH and S from K₂O₂ and H₂S.
Phenomenon occurs:
- During the reaction process, we will see the solid K₂O₂ gradually turn into a white solid (KOH) and sulfur powder (S) if the reaction occurs at a suitable temperature.
- If the reaction occurs at a high temperature, the sulfur powder (S) may burn, producing an orange-yellow color and generating a large amount of heat.