Question

Compare the amount of oxygen required to oxidize methane and ethane completely. Give your answer two ways: gO2/g compound and gO2/gC.

Answer 1

Combustion of methane

CH4(g) + 2O2(g) → CO2(g) + 2H2O(l)

1 mol of CH4 reacts with = 2 moles of O2

16 g of CH4 reacts with = 64 g of O2

gO2/gCH4 = 64/16 = 4

gO2/gC = 64/12 = 5.333

combustion of ethane

C2H6(g) +7/2 O2(g) → 2CO2(g) + 3H2O(l)

1 mol of C2H6 reacts with = 3.5 moles of O2

30 g of C2H6 reacts with = 3.5*32 = 112 g of O2

gO2/gC2H6 = 112/30 = 3.733

gO2/gC = 112/24 = 4.666

In the combustion of ethane gO2/g compound and gO2/gC are required less than combustion of methane.