Limiting Reactants & % Yield Calculations

Front

What is a limiting reactant?

Back

The limiting reactant is the substance that is completely consumed in a chemical reaction, limiting the amount of product that can be formed.

Front

How do you calculate percent yield?

Back

Percent yield = (Actual yield / Theoretical yield) x 100%.

Front

What is theoretical yield?

Back

Theoretical yield is the maximum amount of product that can be produced from a given amount of reactants, based on stoichiometric calculations.

Front

What is actual yield?

Back

Actual yield is the amount of product that is actually obtained from a chemical reaction, measured in the lab.

Front

What does a percent yield of over 100% indicate?

Back

A percent yield over 100% indicates that there may have been an error in measurement or that impurities were present in the product.

Front

What is the significance of a low percent yield?

Back

A low percent yield suggests that the reaction was not efficient, possibly due to incomplete reactions, side reactions, or loss of product during recovery.

Front

In the reaction P4 + 6Cl2 → 4PCl3, if 75.0g of P4 is used, how do you find the theoretical yield of PCl3?

Back

First, determine the molar mass of P4, then use stoichiometry to calculate the moles of PCl3 produced from the moles of P4.

Front

What is the role of stoichiometry in yield calculations?

Back

Stoichiometry allows us to predict the amounts of reactants and products involved in a chemical reaction, which is essential for calculating theoretical yield.

Front

If the theoretical yield of a reaction is 50g and the actual yield is 45g, what is the percent yield?

Back

Percent yield = (45g / 50g) x 100% = 90%.

Front

What is the difference between actual yield and theoretical yield?

Back

Actual yield is what you obtain from the experiment, while theoretical yield is what you expect based on calculations.