Year 10 Science · Unit 2 · Lesson 11
Challenge Worksheet
Learning Goals
Design a mini-experiment
A scientist wants to test: "How does the concentration of hydrochloric acid (HCl) affect the rate of reaction between marble chips (CaCO₃) and HCl?" Plan the investigation below in full.
| What I will change (independent variable) | |
| What I will keep the same (controlled variables, list at least 4) | |
| What I will measure (dependent variable) | |
| Step-by-step method (at least 5 steps) | |
| Safety precautions (at least 2) | |
| My prediction (use collision theory) | |
| Expected shape of the graph (describe the axes and trend) | |
| One limitation of this experiment |
1. In your investigation above, you plan to collect the CO₂ gas and measure its volume over time. Describe the data table you would create, including at least THREE columns with units. Draw a rough sketch of the expected graph shape for TWO different acid concentrations (label which is faster).
2. A catalytic converter in a car provides an example of a heterogeneous catalyst (solid catalyst, gas reactants). Using collision theory, explain why the catalyst increases the rate without being consumed in the reaction.
Wrap Up
In one sentence, what was the main idea of this lesson?