Science>Year 10>Unit 2>Checkpoint 3

Checkpoint 3

This checkpoint tests Block C: collision theory, factors affecting reaction rate (concentration, surface area, temperature, catalysts), practical investigations, data analysis, and industrial applications.

SC5-RXN-02Lessons 11-1510 MC3 Short AnswerCheckpoint 3 of 4
CP3

Coverage

This checkpoint assesses your understanding of what controls how fast chemical reactions occur.

Lesson 11

Collision theory and factors affecting reaction rate.

Lesson 12

Concentration and surface area effects with practical investigations.

Lesson 13

Temperature and catalysts, including enzymes as biological catalysts.

Lesson 14

Analysing reaction rate data, graphs, fair testing and reliability.

Lesson 15

Controlling reactions in industry (Haber process) and nature (enzymes).

MC Score
0 / 10
SA Score
0 / 12
Multiple Choice
Q

Test Your Understanding

UnderstandBand 3

1. According to collision theory, what must happen for a reaction to occur?

AParticles must be at absolute zero temperature
BParticles must collide with sufficient energy and correct orientation
CAll particles must be in the solid state
DParticles must be larger than a certain size
UnderstandBand 3

2. Increasing the concentration of a reactant increases the reaction rate because:

AThe particles become larger
BThe temperature automatically increases
CThere are more particles per unit volume, leading to more frequent collisions
DThe particles move slower
UnderstandBand 3

3. Which change would NOT increase the rate of a reaction?

ADecreasing the temperature
BIncreasing the surface area of a solid reactant
CAdding a catalyst
DIncreasing the concentration of a solution
UnderstandBand 4

4. What happens to a catalyst during a chemical reaction?

AIt is completely used up
BIt becomes part of the product
CIt increases the temperature of the reaction
DIt provides an alternative pathway and is not used up
ApplyBand 4

5. Powdered zinc reacts faster with hydrochloric acid than zinc ribbon. What is the best explanation?

APowdered zinc is more reactive than zinc ribbon
BPowdered zinc has a greater surface area, exposing more particles to collisions
CPowdered zinc increases the concentration of the acid
DPowdered zinc acts as a catalyst
UnderstandBand 4

6. In the Haber process, why is a high temperature NOT used even though it increases the reaction rate?

AHigh temperatures are too dangerous
BHigh temperatures destroy the catalyst
CHigh temperatures are expensive and reduce the yield, so a compromise temperature is used
DHigh temperatures make the reaction too fast to control
UnderstandBand 3

7. Enzymes are described as biological catalysts because they:

ASpeed up chemical reactions in living organisms without being used up
BProvide energy for all cellular processes
CAre consumed during digestion
DIncrease the temperature of the body
ApplyBand 4

8. A graph shows the volume of gas produced over time for a reaction. The curve is steepest at the beginning and levels off. What does this tell you?

AThe reaction speeds up over time
BNo reaction is occurring
CThe temperature is decreasing
DThe reaction is fastest at the start and slows as reactants are used up
UnderstandBand 4

9. Why does increasing temperature increase reaction rate?

AIt increases the size of the particles
BParticles move faster and more collisions have sufficient energy to react
CIt decreases the concentration of reactants
DIt changes the products of the reaction
AnalyseBand 5

10. In an experiment on reaction rate, which variable MUST be controlled to ensure a fair test?

AOnly the independent variable
BOnly the dependent variable
CAll variables except the independent variable
DNo variables need to be controlled
Short Answer
✍

Short Answer Questions

UnderstandBand 3

11. Explain how collision theory accounts for the effect of concentration on reaction rate. Use the terms particles, collisions and frequency in your answer. 4 MARKS

Use all three terms in your book.
ApplyBand 4

12. A student investigates how temperature affects the rate of reaction between sodium thiosulfate and hydrochloric acid. Describe how the student could measure the reaction rate and identify one variable that must be controlled. 4 MARKS

Answer in your book.
AnalyseBand 5

13. Compare the use of enzymes in biological systems to the use of catalysts in industrial processes. Include one similarity and one difference. 4 MARKS

Answer in your book.

Review & Reflect

✓ I can explain...

  • Collision theory in simple terms
  • How concentration affects reaction rate
  • How surface area affects reaction rate
  • How temperature affects reaction rate
  • How catalysts work without being used up

⚠ I need to review...

  • Interpreting reaction rate graphs
  • Fair testing and controlled variables
  • The Haber process trade-offs
  • Enzyme specificity and conditions
  • Calculating averages and spotting anomalies

Mark checkpoint as complete

Tick when you have finished all questions and reviewed your answers.

Module overview · Science subject page