Yield

Cards (5)

What is a yield?
The yield of a chemical reaction describes how much product is made
What does the percentage yield tell you?
How much product is made compared with the maximum that could be made
% Yield = actual mass of product made/Max theoretical mass of product x 100
List some factors that affects percentage yield
Reaction may be reversible
Some reactants may react to give unexpected/unwanted products
Some product may be lost in handling or left in apparatus
Reactants may not be pure
Some product may be lost during its separation from the reaction mixture.
Calcium carbonate decomposes to form calcium oxide + carbon dioxide. A student carries out a reaction and calculates the theoretical yield to be 28g. When they weighed the product, they found it to weigh 22g. Calculate the theoretical yield.
% Yield = actual mass of product made/max theoretical mass of product x 100
= ( 22/28 ) x 100 = 78.6%