Theoretical Yield and Percent Yield (3.3.5)

Question 1

What is Theoretical Yield?

Answer 1

Maximum amount of products that is expected from a given amount of reactants.

Question 2

Percent Yield

Answer 2

(Actual Yield) / Theoretical Yield, * 100.

Question 3

• Theoretical yield is the maximum amount of product that can be made from a given amount of reactants.

Answer 3

• Theoretical yield is the maximum amount of product that can be made from a given amount of reactants.

Question 4

• Percent yield is the actual yield expressed as a percentage of the theoretical yield.

Answer 4

• Percent yield is the actual yield expressed as a percentage of the theoretical yield.

Question 5

Theoretical yield is the maximum amount of product
that can be made from a given amount of reactants.

To calculate theoretical yield, first determine the
limiting reactant. Convert the masses of the
reactants into moles. Use the amount of each
reactant and the coefficients from the balanced
chemical equation to determine the limiting
reactant. In this example, because the reactants
are in a 1:1 ratio, the limiting reactant is ethanol
(0.435 moles).

Finally, calculate the theoretical yield of ethyl
acetate by determining the moles produced (using
the molar ratio with ethanol, a simple 1:1 in this
case). Convert the moles of ethyl acetate to grams
using the molar mass, as shown, to obtain the
theoretical yield of ethyl acetate in grams (38.3 g).

Often, chemical reactions do not produce their
maximum yield. The amount of product produced in
an experiment is the actual yield.

Percent yield is the actual yield expressed as a
percentage of the theoretical yield. Divide the
actual yield by the theoretical yield and multiply by
100 to obtain the percent yield.

The value of the actual yield is always less than the
value of the theoretical yield and thus the percent
yield is always less than 100 %.

However, good chemists get higher percent yields.

Answer 5

Theoretical yield is the maximum amount of product
that can be made from a given amount of reactants.

To calculate theoretical yield, first determine the
limiting reactant. Convert the masses of the
reactants into moles. Use the amount of each
reactant and the coefficients from the balanced
chemical equation to determine the limiting
reactant. In this example, because the reactants
are in a 1:1 ratio, the limiting reactant is ethanol
(0.435 moles).

Finally, calculate the theoretical yield of ethyl
acetate by determining the moles produced (using
the molar ratio with ethanol, a simple 1:1 in this
case). Convert the moles of ethyl acetate to grams
using the molar mass, as shown, to obtain the
theoretical yield of ethyl acetate in grams (38.3 g).

Often, chemical reactions do not produce their
maximum yield. The amount of product produced in
an experiment is the actual yield.

Percent yield is the actual yield expressed as a
percentage of the theoretical yield. Divide the
actual yield by the theoretical yield and multiply by
100 to obtain the percent yield.

The value of the actual yield is always less than the
value of the theoretical yield and thus the percent
yield is always less than 100 %.

However, good chemists get higher percent yields.