Question

CH4 with pressure 10 atm and volume 10 liter at 27^oC is passed into a reactor with 20% excess oxygen, how many moles of oxygen is left in the products?

(a) 2

(b) 4

(c) 6

(d) 8

I had been asked this question in an interview for job.

Asked question is from Material Balances Involving Ideal Gases in portion Recycle, Bypass, Purge, Ideal Gases and Real Gases of Basic Chemical Engineering

Answer 1

Right answer is (b) 4

Explanation: The reaction is CH4 + 2O2 -> CO2 + 2H2O, moles of CH4 = 10*10/(0.0821*300) = 4, => moles of O2 left = 2*4(50/100) = 4.