Reacting with Speed: Understanding Rates of Reaction

• Chemistry
• Upper Secondary (Key Stage 4)
• GCSE

Understanding Rates of Reaction

Learning Objective

At the end of the lesson, you will be able to explain the concept of rates of reaction, understand factors affecting reaction rates, and apply this knowledge to revise for your GCSE exam.

What do you already know about rates of reaction?

Rate of reaction definition

Rates of reaction refer to how quickly a chemical reaction takes place. It is influenced by several factors.

Slide 2: Collision Theory

Collision theory states that for a reaction to occur, particles must collide with sufficient energy and proper orientation.

Slide 3: Factors Affecting Reaction Rates

1. Concentration: Increasing concentration of reactants leads to more frequent collisions. 

 2. Temperature: Higher temperature increases kinetic energy and collision frequency. 

 3. Surface Area: Greater surface area allows for more particle collisions.

Slide 4: Concentration

Higher concentration means more particles in the same volume, leading to increased collision frequency and faster reaction rates.

Slide 5: Temperature

Increasing temperature gives particles more kinetic energy, resulting in faster and more energetic collisions.

Slide 6: Surface Area

Greater surface area provides more opportunities for particle collisions, leading to faster reaction rates.

Slide 7: Graphical Representation

Reaction rates can be represented by graphs showing the change in concentration or mass over time.

What factors can affect the rate of a chemical reaction?

1. Temperature
2. Volume
3. Concentration
4. Surface Area

What is the effect of increasing temperature on the rate of reaction?

1. Decreases
2. Remains unchanged
3. Increases

What is the collision theory?

1. Particles must collide with low energy to initiate a reaction
2. Particles must collide with sufficient energy and proper orientation for a reaction to occur

What is a catalyst?

1. A substance that increases the rate of a chemical reaction without being consumed
2. A substance that decreases the rate of a chemical reaction

What is the unit for the rate of reaction?

1. g/cm³s⁻¹
2. mol/L
3. M/s
4. mol/dm³s⁻¹

What does this graph show?

What is the definition of rate of reaction?

1. The speed at which a reaction takes place
2. The energy change in a reaction
3. The amount of product formed in a reaction
4. The concentration of reactants in a reaction

Which factors can affect the rate of a chemical reaction?

1. Volume of products
2. Temperature
3. Surface area of reactants
4. Concentration of reactants

What is the role of a catalyst in a chemical reaction?

1. To stop the reaction from occurring
2. To increase the rate of reaction
3. To change the products of reaction
4. To decrease the rate of reaction

Which type of reaction is typically faster?

1. Neutralization reactions
2. Exothermic reactions
3. Oxidation reactions
4. Endothermic reactions

How can the rate of a reaction be measured?

1. By observing a color change
2. By monitoring the formation of a product
3. By measuring the temperature change
4. By measuring the decrease in reactant concentration

What is a reaction rate?

1. The temperature at which a reaction occurs
2. The mass of the products formed in a reaction
3. The concentration of reactants in a solution
4. The speed at which reactants are converted into products

What factors can affect the rate of a chemical reaction?

1. Temperature, pressure, volume, and catalysts
2. Temperature, surface area, concentration, and catalysts
3. Pressure, volume, temperature, and concentration
4. Surface area, concentration, pressure, and volume

What is the role of a catalyst in a chemical reaction?

1. To decrease the rate of reaction without being used up
2. To increase the rate of reaction and be used up in the process
3. To increase the rate of reaction without being used up
4. To decrease the rate of reaction and be used up in the process

What is the definition of the rate of a chemical reaction?

1. The measure of how much reactants are used up
2. The measure of how fast reactants are used up or products are formed
3. The measure of how much energy is released during a reaction
4. The measure of how much products are formed

What happens to the rate of a chemical reaction when the temperature is increased?

1. The rate of reaction decreases
2. The rate of reaction remains the same
3. The rate of reaction becomes unpredictable
4. The rate of reaction increases

How does the concentration of reactants affect the rate of a chemical reaction?

1. Higher concentration leads to a slower rate of reaction
2. Higher concentration leads to a faster rate of reaction
3. Concentration does not affect the rate of reaction
4. Lower concentration leads to a faster rate of reaction

What is a catalyst in a chemical reaction?

1. A substance that speeds up the rate of reaction without being used up
2. A substance that changes the type of reactants
3. A substance that is consumed during the reaction
4. A substance that slows down the rate of reaction

Write down 3 things you learned in this lesson.

Have students enter three things they learned in this lesson. With this they can indicate their own learning efficiency of this lesson.

Write down 2 things you want to know more about.

Here, students enter two things they would like to know more about. This not only increases involvement, but also gives them more ownership.

Ask 1 question about something you haven't quite understood yet.

The students indicate here (in question form) with which part of the material they still have difficulty. For the teacher, this not only provides insight into the extent to which the students understand/master the material, but also a good starting point for the next lesson.

Marble chips react with dilute hydrochloric acid to produce carbon dioxide gas.

The rate of this reaction can be changed by changing the size of the marble chips.

Describe how you could investigate what effect using smaller marble chips has on the rate of this reaction. Predict and explain the effect of using smaller marble chips on the reaction rate