Sciences Co-ordinated 0654/61 Oct Nov 2024 | Cambridge IGCSE Past Papers With Mark Scheme

1. Enzyme-Catalyzed Reaction & Hydrogen Peroxide Breakdown | Measuring foam height in different hydrogen peroxide concentrations, experimental accuracy, and improving measurement techniques.

2. Effect of Mouthwash on Saliva pH | Planning an investigation, identifying controlled variables, measuring pH changes, and analyzing results.

3. Thermal Decomposition of Metal Carbonates | Comparing decomposition times for different metal carbonates, identifying reactivity trends, and ensuring safe heating procedures.

4. Electrochemical Cells & Metal Reactivity | Measuring voltage differences between metals, determining reactivity order, and comparing accuracy of different experimental methods.

5. Identifying Aqueous Solutions via Chemical Tests | Conducting flame tests, precipitate reactions, and ammonia tests to determine unknown metal chlorides.

6. Resistance Wire Experiment & Voltage Readings | Measuring potential difference across different wire lengths, identifying anomalies, and plotting a best-fit graph.

7. Density Measurement of Water | Comparing two methods for measuring water density, ensuring accurate volume readings, and calculating density using mass and displacement techniques.