calculate the yield of CO2 if 30.g of C2H6 reacts with 14.0g of O2. Show work

2C2H6 + 7O2 ==> 4CO2 + 6H2O

mols C2H6 = grams/molar mass
mols O2 = grams/molar mass.
Using the coefficients in the balanced equation convert mols C2H6 to mols CO2.
Do the same for mols O2.
It is likely that these two values will not agree which means one of them is wrong. The correct value in limiting reagent problems is ALWAYS the smaller value and the reagent producing that value is the limiting reagent.
Convert the smaller value to grams CO2. This is the theoretical yield.