Question

Find the amount of carbon dioxide produced by the combustion of 20g of methane.

(a) 44g

(b) 20g

(c) 66g

(d) 22g

I got this question during a job interview.

Origin of the question is Stoichiometry and Stoichiometric Calculations in section Chemistry Basic Concepts of Chemistry – Class 11

Answer 1

The correct choice is (c) 66g

The explanation is: The chemical balanced equation for combustion of methane is CH4(g) + 2O2(g)  →CO2(g) + 2H2O(g). From the above equation, 1 mole of methane gives 1 mole of carbon dioxide. But 20g of methane = 1.25 moles, therefore it gives 1.25 moles of carbon dioxide = 44(1.5) = 66g.