what is the weight of oxygen required for the complete combustion of 2.8kg of ethylene? plz answer urgently....

Combustion of Ethylene can be written as:

C₂H₄ + 3 O₂ → 2 CO₂ + 2 H₂O

0.028 kg (Molar mass of ethylene) needs 3 x 0.032 = 0.096 kg of oxygen.

1 kg of ethylene will need (0.096/0.028) =  3.42 kg of oxygen.

So, 2.8 kg of ethylene will need (3.42 x 2.8) =  9.6 kg of oxygen.