Question

A laboratory manual gave precise instructions for carrying out the reaction described by the chemical equation, C2H6O + O2 C2H4O2 + H2O. It stated that if you bubble oxygen gas through a solution containing the reactant for 24 hours then the yield of C2H4O2 would be 7.50% of the theoretical amount. If you desire to produce 700. grams of the C2H4O2 in a single batch, how many kg of C2H6O should you begin with?

Answer 1

C2H6O + O2 ---> C2H4O2 + H2O

using the molar masses:-
24+ 6 + 16 g of C2H6O  produces 24 + 4 + 32 g C2H4O2    (theoretical)
 46 g produces 60g 

60 g C2H4O2 is produced from 46g C2H6O
1g      .     .................................46/60 g 
 700g     .................................    (46/60) * 700  Theoretically

But as the yield is only 7.5% 

the required amount is    ((46/60) * 700 ) / 0.075 =  7155.56 g 

=  7.156 kg to nearest gram.  Answer