Chemistry - Mole Concept Question with Solution | TestHub

To find the mass of oxygen required, first write the balanced combustion equation for ethylene (C₂H₄):

C₂H₄ + 3O₂ $\to$ 2CO₂ + 2H₂O

From the stoichiometry, 1 mole of C₂H₄ reacts with 3 moles of O₂.

Molar mass of C₂H₄ = $2(12.01)+4(1.01)=28.06$ g/mol

Molar mass of O₂ = $2(16.00)=32.00$ g/mol

Moles of C₂H₄ = $1400$ g / $28.06$ g/mol $\approx 49.89$ mol

Moles of O₂ required = $3\times 49.89$ mol $\approx 149.67$ mol

Mass of O₂ required = $149.67$ mol $\times 32.00$ g/mol $\approx 4789.44$ g $\approx 4.8$ kg.

The final answer is $\boxed{4.8Kg}$.