Free RPAL Reactants Questions and Answers — Questions and Answers
Question 1: What is a reactant in a chemical reaction?
- A substance that speeds up the reaction without being consumed
- A substance that is formed as a result of the reaction
- A substance that undergoes change during a reaction (Correct answer)
- A byproduct of the reaction
Correct answer: A substance that undergoes change during a reaction
Reactants are the starting materials in a chemical reaction that are transformed into products.
Question 2: Which of the following correctly describes the role of reactants in a chemical equation?
- Reactants are always present in larger quantities than products
- Reactants are placed on the right side of the equation
- Reactants are the substances that react to form new products (Correct answer)
- Reactants determine the color of the products
Correct answer: Reactants are the substances that react to form new products
Reactants participate in the chemical reaction, and their interaction results in the formation of products.
Question 3: In the chemical equation 2H₂ + O₂ → 2H₂O, which are the reactants?
- H₂O
- H₂ and O₂ (Correct answer)
- H₂
- O₂ and H₂O
Correct answer: H₂ and O₂
In this equation, hydrogen (H₂) and oxygen (O₂) are the reactants that combine to form water (H₂O).
Question 4: If you start a reaction with 5 moles of reactant A and 3 moles of reactant B, but only 2 moles of reactant A are required, what happens to the excess reactant A?
- It is completely used up
- It becomes a product
- It remains unreacted as a leftover (Correct answer)
- It speeds up the reaction
Correct answer: It remains unreacted as a leftover
The excess reactant A that is not required for the reaction remains unreacted as a leftover.
Question 5: How can you identify the limiting reactant in a chemical reaction?
- It is the reactant present in the smallest quantity
- It is the reactant that produces the least amount of product (Correct answer)
- It is the reactant that is left over after the reaction
- It is the reactant that causes the reaction to stop
Correct answer: It is the reactant that produces the least amount of product
The limiting reactant is the one that is completely consumed first, limiting the amount of product that can be formed.
Free RPAL Reactants Questions and Answers
What is a reactant in a chemical reaction?