Chemistry 9701/34 Oct Nov 2016 | Cambridge AS Level Past Papers With Mark Scheme

1. Magnesium and Hydrochloric Acid Reaction:
- Measuring the volume of hydrogen gas produced when magnesium reacts with hydrochloric acid, and calculating the relative atomic mass of magnesium (Ar of Mg) from the reaction.
- Steps include weighing the magnesium, using a burette to add hydrochloric acid, and collecting hydrogen gas to calculate moles and Ar of magnesium.

2. Titration with Sodium Carbonate:
- Using a titration to find the amount of hydrochloric acid remaining after reacting with magnesium. The amount of sodium carbonate solution used in the titration will help calculate the leftover acid.
- Includes detailed steps for performing titrations, calculating the amount of HCl that reacted with magnesium, and determining the moles of HCl and Ar of magnesium.

3. Error Analysis:
- Calculating the percentage error in the mass and volume measurements and suggesting ways to reduce these errors in the experiment.

4. Effect of Temperature on Results:
- Discussing how the temperature of the room could impact the reaction, particularly how a lower temperature could affect the volume of gas produced, leading to a lower Ar of magnesium.

5. Qualitative Analysis:
- Identifying compounds like ethanol, propanal, and propanone based on reactions with reagents such as acidified potassium manganate(VII), potassium iodide, and Tollens' reagent.
- Performing tests to identify cations and anions, and observing changes in color, precipitate formation, or gas release.