Answer: D
2C2H4 + 10 O2 à 4 CO2 + 2 H2O
Make sure write the balanced combustionreaction first then
7g x (1mol/28.1g) x ( 4mol CO2/2mol C2H2) x(22.4 dm3/1mol) => simplify => (2 x 22.4 x 7.00) 28.1
(2 x22.4 x 7.00) / 28.1
