Question

Determine the theoretical yield of CO2 (in grams) for the reaction below if you have 18.0 g of C2H4 and 45.0 g of O2.

C2H4(g) + 3 O2(g)à2 CO2(g) + 2 H2O(l)

Answer 1

moles of C2H4 = mass / molar mass = 18.0 g / 28.0532 g/mol = 0.6416 mol

moles of O2 = 45 g/ 32 g/mol = 1.40 mol

from the balanced equation

1 mole of C2H4 required 3 moles of O2 accordingly

0.6416 mol required 3 x 0.6416 = 1.9248 mol O2

but we have 1.40 mol

so limiting agent is C2H4

from balanced equation

1 mol of C2H4 will produce 2 mol of CO2 accordingly

0.6416 mol produces 2 x 0.6416 mol = 1.2832 moles of CO2

theritcal mass of CO2 = 1.2832 mol x 44 g/mol = 56.4608 grams