Question

How many moles of co2 are produced when 5.40 mol of ethane are burned in an excess of oxygen?

Answer 1

Reaction of ethane combustion:

2C2H6 (g) + 7O2 (g) ----> 4CO2 (g) + 6H2O 

According to the reaction, we can see that C2H6 and CO2 have following stoichiometric ratio: 

n(C2H6) : n(CO2) = 2 : 4

If we know the number of moles of ethane we can calculate moles of carbon dioxide:

2 x n(CO2) = 4 x n(C2H6)

n(CO2) = 2 x n(C2H6)

n(CO2) = 2 x 5.4 = 10.8 mole of CO2 are produced