Chemistry 9701/31 Oct Nov 2018 | Cambridge AS Level Past Papers With Mark Scheme

1. Finkelstein Reaction Setup: Use of dry propanone as a solvent for nucleophilic substitution reactions between halogenoalkanes and halides, enhancing reaction efficiency.
2. Reactivity and Solubility in Propanone: Explaining the high yield of the Finkelstein reaction due to the differential solubility of NaBr and NaI in propanone, which drives the reaction forward.
3. Safety Measures in Laboratory: Identifying additional precautions, such as avoiding inhalation of toxic gases and managing highly flammable substances during the experiment.
4. Reaction Rate Experiment: Calculating and analyzing the rate of reaction between NaI and halogenoalkanes, considering the volume of reactants and measuring time for the reaction to occur.
5. Accuracy and Inaccuracy in Measurements: Identifying potential sources of error in the measurement of reaction times and suggesting improvements to minimize inaccuracies in the experiment.
6. SN1 and SN2 Mechanism Comparison: Understanding the differences in reaction rates and mechanisms (SN1 vs. SN2) and how they influence experimental outcomes with different halogenoalkanes.