Balanced chemical equation:
2 C2H2 + 5 O2 = 4 CO2 + 2 H2O
2 moles C2H2 ---------------- 5 moles O2
moles C2H2 ------------------ 84 moles O2
moles C2H2 = 84 * 2 / 5
molesC2H2 = 168 / 5 => 33.6 moles of C2H2
He used prisms to demonstrate how white light is in fact made
1) convert Celsius to Kelvin
24 + 273 = 297
2) convert kPa to atm
62.2 / 101.3 = 0.614
3) plug numbers into the ideal gas law formula
Answer: 0.088 mols