Excess Reactant Chemistry Worksheet
Grade 12 Chemistry worksheet focusing on understanding and calculating excess reactants in chemical reactions.
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Excess Reactant Chemistry
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Read each question carefully and answer to the best of your ability. Show all your work for calculation problems.
1. In a chemical reaction, the reactant that is not completely consumed is called the:
Limiting reactant
Excess reactant
Product
Catalyst
2. Which of the following is true about the excess reactant?
It determines the maximum amount of product that can be formed.
Some of it will be left over after the reaction is complete.
It is always the reactant with the smaller initial mass.
It stops the reaction when it is completely consumed.
3. The concept of an excess reactant is important because it helps to maximize the yield of the desired .
4. To identify the excess reactant, one must first determine the reactant.
5. Consider the reaction: 2H₂(g) + O₂(g) → 2H₂O(l). If you start with 10.0 moles of H₂ and 3.0 moles of O₂, identify the limiting reactant and the excess reactant.
6. For the reaction in question 5, calculate the amount (in moles) of the excess reactant that remains after the reaction is complete.
7. The excess reactant always has a larger initial mass than the limiting reactant.
True
False
8. Adding more of the excess reactant will increase the amount of product formed.
True
False
9. Given the balanced chemical equation: 2Al(s) + 3Cl₂(g) → 2AlCl₃(s). If 54.0 g of aluminum reacts with 71.0 g of chlorine gas, determine: a) The limiting reactant. b) The excess reactant. c) The mass (in grams) of the excess reactant that remains after the reaction is complete.