Question

For the following balanced chemical reaction:
C7H16 + 11O2 => 7CO2 + 8H2O

If the reaction of 48.47 grams of C7H16 and 176.25 grams of O2 produces 70.54 grams of CO2 what is the % yield?

Answer 1

You need to calculate first the theoretical yield, then you can calculate the % yield.
To calculate the theoretical yield you have to find what is the limiting reactant, if it is the C7H16 or the O2, most of the times the O2 is in excess but you have to verify.
To identify the limiting reactant you have to calculate how many grams of CO2 you theoretically can obtain with either of the reactants C7H16 or the O2. The reactant that produce less amount of CO2 is the limiting reactant and the amount of CO2 produced will be the theoretical yield.
Finaly to calculate the % yield, multiply the real yield by 100 and divide by the theoretical yield.