Question

What is the weight of oxygen required for the complete combination of 2.8 kg of ethylene?

Answer 1

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.

Answer 2

0.028 kg ( molar mass of Ethylene) needs

$3 \times 0.032 = 0.096 \: kg \: of \: oxyen \:$
1kg of ethylene will need (0.096/0.028)=3.42kg of oxygen. So 28kg of ethylene will need (3.42*2.8=9.6kg of oxygen.