Give the systematic names of the alkanol and the carboxylic acid that are required to synthesise propyl propanoate - VCE - SSCE Chemistry - Question 4 - 2012 - Paper 1

The balanced chemical equation for the synthesis of propyl propanoate is:

$$ext{CH}_3 ext{CH}_2 ext{CH}_2 ext{OH} + ext{CH}_3 ext{CH}_2 ext{COOH} \ ightarrow \ ext{CH}_3 ext{CH}_2 ext{COOCH}_2 ext{CH}_2 ext{CH}_3 + ext{H}_2 ext{O}$$

This equation represents the esterification reaction between 1-propanol and propanoic acid.

1. Mix Reactants: Combine 1-propanol and propanoic acid in a reaction vessel.

2. Add Catalyst: Introduce concentrated sulfuric acid (H2SO4) as a dehydrating agent to promote the esterification reaction.

3. Heating: Heat the mixture gently to encourage the reaction, ensuring to allow for removal of water formed, as it can shift the equilibrium.

4. Separation: After the reaction is complete, the mixture containing the product, unreacted reactants, and by-products needs to be analyzed.

5. Purification: Use fractional distillation to purify the propyl propanoate. This method separates the product based on its boiling point.

An annotated flow chart can visually demonstrate this synthesis process, clearly illustrating each step, including the reagents used.

One method to verify the purity of propyl propanoate is through Infrared (IR) Spectroscopy. By analyzing the IR spectrum of the synthesized compound, specific absorption peaks corresponding to the functional groups present in propyl propanoate can be identified. For pure propyl propanoate, we expect to see characteristic peaks, such as:

• A strong peak around 1730 cm⁻¹ for the carbonyl (C=O) group,
• A peak around 1150-1200 cm⁻¹ for the C-O stretching,

Any deviations or additional peaks may indicate the presence of impurities.