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

Answer:

Percentage yield =  25%

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%