Combustion of acetylene :
molar mass acetylene ( C₂H₂ ) = 26.0 g/mol and CO₂ = 44.0 g/mol
2 C₂H₂ + 5 O₂ ---> 4 CO₂ + 2 H₂O
2 moles C₂H₂ --------> 4 moles CO₂
? moles C₂H₂ --------> 1.10 moles CO₂
moles C₂H₂ = 1.10 * 2 / 4
moles C₂H₂ = 0.55 moles of C₂H₂
Mass acetylene:
m = n * mm
m = 0.55 * 26.0
m = 14.3 g
hope this helps!