Chemistry 9701/12 Oct Nov 2019 | Cambridge AS Level Past Papers With Mark Scheme

1. Titration to Determine Concentration of Hydrochloric Acid: A method for determining the concentration of HCl using magnesium and calculating the moles of hydrogen gas produced, followed by using these values to calculate the acid concentration.
2. Improvements in Experimental Accuracy: Suggestions to improve the experiment, such as using magnesium ribbon instead of powder and increasing the mass of magnesium, with explanations on how these changes would impact the accuracy of the results.
3. Effects of Using Less Magnesium: Understanding how using less magnesium than calculated could affect the concentration results, with an explanation on the consequences.
4. Titration for HCl Concentration Determination: Using titration with sodium hydroxide to further determine the concentration of HCl and correcting for any experimental errors such as maximum volume measurement inaccuracies.
5. Hydrated Salt Analysis: Analyzing hydrated salts using tests to identify cations and anions, including reactions with reagents like barium nitrate and sodium hydroxide, to determine the formula and water content in a hydrated salt.
6. Calculating the Number of Moles and Concentration: Calculations for determining the moles of various substances, including sodium hydroxide and hydrochloric acid, and explaining the results in terms of molar concentration and experimental setups.