H2O2 decomposes to H20 and O2 If 32g of oxygen is produced how many grams of H2O2 were decomposed?

Answer 1

Stoichiometry.

2H2O2 --> 2H2O + O2

Two moles of H2O2 gives me one mole of O2, for a mole ratio of

2 mol H2O2/1 mol O2

Change the 32 g of O2 produced to moles of O2 (one mole) and multiply by the mole ratio to give two moles of H2O2, multiply the two moles of H2O2 by the molar mass (34 g/mol) and we get that 68 g of H2O2 must have been decomposed. Works for all sorts of these problems.