Theoretical Yield in Chemistry
Explore theoretical yield, limiting reactants, and percentage yield in chemical reactions for Grade 9 science.
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Theoretical Yield in Chemistry
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Read each question carefully and answer to the best of your ability. Show all your work for calculations.
1. What does 'theoretical yield' represent in a chemical reaction?
The actual amount of product obtained in an experiment.
The maximum amount of product that can be formed from given reactants.
The amount of reactant left over after a reaction.
The speed at which a reaction occurs.
2. Which factor is NOT considered when calculating theoretical yield?
Stoichiometry of the balanced equation.
Molar masses of reactants and products.
Experimental errors and side reactions.
Limiting reactant.
3. The reactant that is completely consumed in a chemical reaction and limits the amount of product formed is called the .
4. The yield is the amount of product actually obtained from an experiment.
5. Explain the difference between theoretical yield and actual yield.
6. Consider the reaction for the synthesis of ammonia: N₂(g) + 3H₂(g) → 2NH₃(g)
If you start with 28.0 g of nitrogen (N₂) and 6.0 g of hydrogen (H₂):
a. Which is the limiting reactant?
b. Calculate the theoretical yield of ammonia (NH₃) in grams.
Molar masses: N₂ = 28.0 g/mol, H₂ = 2.0 g/mol, NH₃ = 17.0 g/mol
7. A percentage yield of 100% is common in most laboratory experiments.
True
False
8. An experiment to produce calcium carbonate (CaCO₃) has a theoretical yield of 50.0 g. If the actual yield obtained in the lab was 45.0 g, what is the percentage yield?