📚 Part 1: Key Vocabulary Matching

Instructions: Match each term to its correct definition by drawing a line between them.

Rate of reaction

Catalyst

Surface area

Concentration

Activation energy

How much acid is dissolved in a solution

Minimum energy needed for a reaction to start

How fast a chemical reaction happens

Amount of exposed area on marble chips

Speeds up reactions without being used up

6. Fill in the blanks using words from the box above:

When marble chips react with acid, we can increase the _____________ by using smaller chips because they have more _____________. A _____________ could speed up the reaction without being consumed.

🧪 Part 2: Practical Method & Results

7. Number the steps (1-6) to show the correct order for the marble chips and acid experiment:

Record the volume of gas every 30 seconds

Add marble chips to the acid quickly

Set up gas syringe connected to conical flask

Measure 50cm³ of hydrochloric acid into flask

Start the stopwatch immediately

Continue until no more gas is produced

8. Complete this results table with the missing headings and units:

Time (__________)	_____________ (cm³)
0	0
30	15
60	25

9. Safety considerations: Tick all the safety measures needed for this experiment:

Wear safety goggles

Use a fume cupboard

Wear gloves when handling acid

Keep a fire extinguisher nearby

📊 Part 3: Graph Interpretation & Exam Practice

10. A student plotted volume of gas against time. The graph shows a steep slope at the start, then gradually levels off. Explain why this pattern occurs:

Sentence starter: At the beginning, the reaction is fast because...

Then: The reaction slows down because...

11. A student wants to make the reaction faster. Suggest TWO changes they could make and explain why each would work:

Change 1: _________________________________

Explanation:

Change 2: _________________________________

Explanation:

12. Extension Challenge: A student's results showed an anomalous reading at 90 seconds where the gas volume suddenly dropped. Suggest what might have caused this error and how to prevent it: