Write and balance the chemical reaction. Express your answer as a chemical equation. Identify all of the phases in your answer.?

Hydrogen peroxide (H2O2) decomposes in the presence of a catalyst to form water and oxygen. The catalyst was added to 5.60 mL of a hydrogen peroxide solution at 20.0 ∘C , and 49.5 mL of gas was collected over water at a total pressure of 764.4 mmHg . Look up the vapor pressure of water under these conditions in the table.

Write and balance the chemical reaction (note: catalysts do not appear in balanced chemical equations).
Express your answer as a chemical equation. Identify all of the phases in your answer.