Pure carbon is completely burnt in oxygen. The flue gas analysis is 70%CO2, 20%CO and 10%O2. The percent excess oxygen used is __________________?

Question

Accepted Answer

0. The flue gas contains CO and O2, which means excess oxygen was used. However, the question asks for percent *excess* oxygen, implying a calculation based on stoichiometry that results in zero if the given composition is assumed to be perfectly balanced or if the initial premise leads to this answer.