Question

Give the percent yield when 28.16 g of CO2 are formed from the reaction of 4.000 moles of C8H18 with 4.000 moles of O2.

2 C8H18 + 25 O2 → 16 CO2 + 18 H2O

Answer 1

Percentage yield = 25%

Step-by-step explanation:

Given data:

Moles of C₈H₁₈ = 4 mol

Moles of O₂ = 4 mol

Actual yield of CO₂ = 28.16 g

Percentage yield = ?

Solution:

Chemical equation:

2C₈H₁₈ + 25 O₂ → 16CO₂ + 18H₂O

Now we will compare the moles of CO₂ with O₂ and C₈H₁₈.

C₈H₁₈ : CO₂

2 : 16

4 : 16/2×4=32 mol

O₂ : CO₂

25 : 16

4 : 16/25×4=2.56 mol

Mass of CO₂:

Mass = number of moles× molar mass

Mass = 2.56 mol ×44 g/mol

Mass = 112.64 g

Percentage yield:

Percentage yield = Actual yield /theoretical yield × 100

Percentage yield = 28.16 g / 112.64 g× 100

Percentage yield = 0.25× 100

Percentage yield = 25%