105 Gases and Stoichiometry2 H2O2(liq) 2 H2O(g) + O2(g) Decompose 1.1 g of H2O2in a flask with a volume of 2.50 L. What is the pressure of O2at 25 oC? Of H2O? Solution Strategy: Calculate moles of H2O2and then moles of O2and H2O. Finally, calc. P from n, R, T, and V.