Year 10 Science · Unit 2 · Lesson 11

What Affects Reaction Rate?

Foundation Worksheet

Name

Date

Class

Learning Goals

Define reaction rate and describe the conditions required for a successful collision.
Name and describe four factors that affect reaction rate.
Use collision theory to explain how each factor changes the rate.

Warm Up

Match each term to its definition

Draw a line connecting each term on the left to its correct definition on the right. Or write the matching letter next to each term.

Term	Your answer	Definition
Reaction rate		A. A substance that increases reaction rate by providing an alternative pathway with lower activation energy, and is not consumed.
Collision theory		B. The amount of solute (particles) dissolved per litre of solution, more particles means more collisions.
Activation energy		C. How fast reactants are converted into products, measured by change in amount per unit time.
Concentration		D. The area of a substance exposed to another reactant, larger area means more particles available to collide.
Surface area		E. The minimum energy that colliding particles must have for a reaction to occur.
Catalyst		F. The idea that reactions occur when particles collide with sufficient energy and the correct orientation.

Your Turn

Fill the gap

Choose the correct word from the word bank to complete the passage. Each word is used once. Two words will not be used.

collision theory activation energy concentration surface area temperature catalyst pressure orientation kinetic energy volume

According to , a chemical reaction can only occur when particles collide with enough energy, called the and with the correct . Increasing the of a solution adds more dissolved particles per litre, increasing the number of collisions per second. Crushing a solid into a powder increases the exposed to the reactant, also speeding the reaction. Raising the gives particles more , so more collisions succeed. Adding a provides an alternative pathway that needs less energy, so more collisions are successful without changing the temperature.

Show What You Know

1. List FOUR factors that can increase the rate of a chemical reaction. For each one, state ONE way you could change it in a school laboratory experiment.

Recall 2 marks

2. Why must a collision have the correct orientation as well as sufficient energy for a reaction to occur? Give a simple everyday analogy to help explain your answer.

Recall 2 marks

Wrap Up

In one sentence, what was the main idea of this lesson?