Question

In the reaction below, hydrogen peroxide decomposes to water. MM H2O2 = 34.02 g/mol MM H2O = 18.02 g/mol MM O2 = 32 g/mol 2H2O2 → 2H2O + O2 If 14.3 moles of H2O2 is decomposed, how many grams of oxygen gas are produced? Show ALL your work to get full credit.

Answer 1

Answer: 228.8 g of O2 are produced

Work:

1) Write the give balanced chemical equation:

2H2O2 → 2H2O + O2

2) molar ratios

2 mol H2O2 : 2 mol H2O :1 mol O2

3) proportion with the unknown quantity number of moles of O2:

          x                      1 mol O2
---------------------- = -----------------------
 14.3 mol H2O2        2 mol H2O2

4) Solve for x:

x = 1 mol O2 * 14.3 mol H2O2 / 2 mol H2O2 = 7.15 mol O2

5) Use the molar mass of O2 to convert 7.15 mol O2 to grams

molar mass of O2 = 2 * atomic mass of O = 2 * 16.00 g/mol = 32.00 g/mol

molar mass = mass in grams / number of moles

=> mass = molar mass * number of moles

mass of O2 =  32.00 g / mol * 7.15 mol = 228.8 g

Answer: 228.8 g