New
New
Year 10
Edexcel
Higher

Catalysts and rate

I can describe what a catalyst does and explain how it affects the rate of reaction in terms of activation energy, and justify its use for a reaction based on experimental results.

New
New
Year 10
Edexcel
Higher

Catalysts and rate

I can describe what a catalyst does and explain how it affects the rate of reaction in terms of activation energy, and justify its use for a reaction based on experimental results.

Lesson details

Key learning points

  1. A catalyst affects the reaction rate without being used up.
  2. A catalyst reduces the activation energy needed for a reaction.
  3. With a catalyst present, more collisions between reactants result in the formation of product(s).
  4. Enzymes are biological catalysts.
  5. Catalysts vary in efficiency; qualitative data helps evaluate effectiveness.

Common misconception

Catalysts increase the amount of product formed.

Catalysts do not affect the quantity of products formed. They increase the rate at which the products are formed.

Keywords

  • Catalyst - A catalyst is a chemical that increases the rate of a reaction without itself being used up.

  • Activation energy - The minimum energy that the particles must have in order to react is known as the activation energy.

  • Reaction profiles - Reaction profiles are diagrams that show the energy of the reactants and products in a chemical reaction.

  • Qualitative data - Qualitative data is information that describes qualities or characteristics that cannot be measured with numbers.

Rochelle salts is a good demonstration to show that catalysts are not used up in the reaction. Elephants toothpaste is a good demonstration for showing how catalysts increase the rate of reaction.
Teacher tip

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
Which label is missing from this reaction profile?
An image in a quiz
reaction
energy
Correct answer: reactants
products
activation energy
Q2.
Which label is missing from the y-axis on this reaction profile?
An image in a quiz
Correct Answer: energy
Q3.
Catalysts provide an alternative route for a reaction with a lower activation energy. What is activation energy?
the energy all reactant particles contain
the maximum energy that particles can contain
the minimum energy that particles can contain
the maximum energy that the particles must have in order to react
Correct answer: the minimum energy that the particles must have in order to react
Q4.
Which of the following is an example of an enzyme?
iron
platinum
Correct answer: lipase
aluminium
Q5.
How could we increase the rate of a chemical reaction?
by decreasing the frequency of successful collisions
Correct answer: by increasing the frequency of successful collisions
lowering the temperature so that particles have less energy
Correct answer: raising the temperature so that particles have more energy
Correct answer: providing a pathway for particles to react with a lower activation energy
Q6.
Catalysts have many uses, such as being used in catalytic converters in cars. Which of the following statements about catalysts are correct?
Catalysts have to be replaced after each reaction.
Correct answer: Catalysts are not used up in chemical reactions.
Correct answer: Catalysts increase the rate of reaction.
Catalysts decrease the rate of reaction.

6 Questions

Q1.
Which of the following will increase the rate of a chemical reaction?
Correct answer: increasing the concentration of reacting solutions
decreasing the surface area of a solid reactant
decreasing the temperature
Correct answer: adding a catalyst
Correct answer: increasing the pressure of reacting gases
Q2.
How does a catalyst affect the activation energy of a reaction?
it increases the activation energy
Correct answer: it decreases the activation energy
it eliminates the activation energy
it has no effect on the activation energy
Q3.
What are enzymes?
chemical catalysts made in laboratories
Correct answer: biological catalysts that speed up reactions in living organisms
catalysts that decrease reaction rates
catalysts that increase the activation energy
Q4.
Which of the following statements about catalysts are correct?
Catalysts all have the same efficiency.
Correct answer: Qualitative data can be used to evaluate the effectiveness of catalysts.
Correct answer: When a catalyst is present more collisions between reactants result in a product
When a catalyst is present less collisions between reactants result in a product
Q5.
Why are catalysts important in industrial processes?
they slow down reactions to save energy
they are expensive and increase costs
Correct answer: they increase the reaction rate and reduce energy consumption
they are used up, adding to waste
Q6.
Which label shows the activation energy for the reaction when a catalyst has been used?
An image in a quiz
A
B
Correct answer: C
D