Using the following equation, #2C_2H_6 + 7O_2 -> 4CO_2 + 6H_2O#, if 2.5 g #C_2H_6# react with 170 g #O_2#, what is the limiting reactant?

1 Answer
May 24, 2017

Clearly, ethane is the limiting reagent. Why #"clearly"#?

Explanation:

You have the stoichiometric equation, which tells you, unequivocally, that 2 equiv ethane reacts with 7 equiv dioxygen gas (alternatively 1 equiv ethane reacts with 3.5 equiv #O_2#).

#"Moles of ethane"=(2.5*g)/(30.1*g*mol^-1)=0.083*mol#.

#"Moles of dioxygen"=(170*g)/(32.0*g*mol^-1)=5.3*mol#.

There is a stoichiometric EXCESS of dioxygen gas.

Can you tell us how much carbon dioxide would be produced given complete combustion?