A reactor is supplied with 20 moles of C, and it undergoes following reactions C + 0.5O2 -> CO and C + O2 -> CO2, if 10 moles of CO2 was produced and 5 moles of C remains unreacted, what are the number of moles of CO produced?

Correct Answer: 5
Extent of second reaction = (10 – 0)/1 = 10, => moles of C reacted in second reaction = 10*1 = 10, => moles of C reacted in first reaction = 20 – 10 – 5 = 5, => extent of first reaction = (0 – 5)/(-1) = 5, => moles of CO produced = 5*1 = 5.