GATE 2023 ES – Question 63
Waste ultimate composition by mass is 48%C,6%H,35%O,6%N,5%ash. For1 kg burned, assuming combustion air contains only oxygen/nitrogen, find maximum CO₂ in kg, to three decimals.
Practise this question in The GATE Grind →
Show answer and explanation
Correct answer: 1.700 to 1.800
Explanation
All available waste carbon becomes CO₂ under complete oxidation. Carbon mass is .48 kg, and the CO₂/carbon molar-mass ratio is 44/12. Therefore maximum CO₂ is $.48(44/12)=\mathbf{1.760}$ kg. Air adds no carbon under the stipulated composition, so hydrogen, oxygen, nitrogen and ash do not increase this carbon-derived maximum.