Question

A reactor is supplied with 45 moles of C, and it undergoes following reactions C + 0.5O2 -> CO and C + O2 -> CO2, if 25 moles of CO2 was produced and 6 moles of C remains unreacted, what are the number of moles of CO produced?

(a) 6

(b) 9

(c) 14

(d) 17

The question was asked during an internship interview.

My question is based upon Processes Involving Multiple Units topic in division The Chemical Reaction Equation & Stoichometry, Material Balances for Processes Involving Reaction and Multiple Units of Basic Chemical Engineering

Answer 1

Right option is (c) 14

Easy explanation: Extent of second reaction = (25 – 0)/1 = 25, => moles of C reacted in second reaction = 25*1 = 25, => moles of C reacted in first reaction = 45 – 25 – 6 = 14, => extent of first reaction = (0 – 14)/(-1) = 14, => moles of CO produced = 14*1 = 14.