Pearson International A Level Chemistry Core Practical 7: Oxidise propan-1-ol to propanal and propanoic acid

This core practical is part of Pearson's practical-learning programme. The method below is one defensible implementation, not a confidential instruction sheet. Centres may adapt equipment while preserving the scientific purpose, controls, measurements and safety requirements.

Aim and scientific principle

Control oxidation and product removal so the same primary alcohol can yield an aldehyde or a carboxylic acid.

Begin by translating the title into a testable question. Identify what is deliberately changed, what is measured directly, what is calculated and what must remain controlled. Predict a relationship only after naming the mechanism. A prediction without a reason is weak; a reason without measurable variables cannot guide a practical design.

Apparatus and setup

Use reaction flask, condenser or distillation head, addition apparatus, heat source, oxidising mixture, anti-bumping granules and collection vessel. Select every measuring instrument by range and resolution, not by name alone. Draw a labelled scientific setup that shows the working geometry and exactly where readings are taken. Include a control or blank when it distinguishes the target effect from drift, contamination or background response.

Before collecting results, check zero readings, calibration, leaks, alignment or sterility as relevant. Record the instrument resolution beside the first raw-data table. If a digital device displays more digits than its underlying accuracy supports, do not treat every digit as equally certain.

Method

1. Choose distillation for aldehyde collection or reflux for further oxidation to acid.
2. Add oxidant at a controlled rate and heat using an appropriate non-flame source.
3. For propanal, distil product as it forms; for propanoic acid, reflux before isolation.
4. Use chemical or spectroscopic evidence to distinguish product functional groups.

Plan the analysis before starting. This reveals whether an additional measurement is needed for a derived quantity and prevents a completed experiment from lacking a mass, length, concentration, background or calibration value. A method should be detailed enough for another trained student to reproduce, while avoiding decorative steps that do not affect validity.

Variables and controls

• Independent variable: distillation or reflux conditions and oxidant availability.
• Dependent variable: product identity, yield or analytical response.