Photo AI
Analyse how a student could design a chemical synthesis process to be undertaken in the school laboratory - HSC - SSCE Chemistry - Question 33 - 2022 - Paper 1
Question 33
Analyse how a student could design a chemical synthesis process to be undertaken in the school laboratory. In your response, use a specific process relating to the s... show full transcript
Worked Solution & Example Answer:Analyse how a student could design a chemical synthesis process to be undertaken in the school laboratory - HSC - SSCE Chemistry - Question 33 - 2022 - Paper 1
Step 1
selection of reagent(s)
Answer
The process to be undertaken is esterification, which synthesizes the organic compound methyl ethanoate from methanol and ethanoic acid. The reagents selected for this reaction are:
- Ethanoic Acid: A carboxylic acid which reacts with alcohols to form esters.
- Methanol: An alcohol that readily reacts with the carboxylic acid.
- Concentrated Sulfuric Acid (H₂SO₄): This is used as a catalyst to speed up the reaction.
Step 2
reaction conditions
Answer
The esterification reaction should be performed under reflux conditions. This entails heating the mixture with a reflux condenser to prevent loss of volatile components. The conditions include:
- Temperature: A high temperature is required to increase the reaction rate.
- Time: The reaction should be allowed to proceed for approximately 30–60 minutes to ensure complete conversion.
Step 3
any potential hazards and any safety precautions to minimise the risk
Answer
Safety considerations are crucial:
- Flammability: Both methanol and ethanoic acid are flammable, so it is essential to work away from open flames. Use a heating mantle instead of a Bunsen burner.
- Corrosiveness: Concentrated sulfuric acid is corrosive, and liquid carboxylic acids are harmful. Safety goggles and gloves should be worn at all times to prevent skin and eye contact.
Step 4
yield and purity of the product(s)
Answer
To maximize the yield and purity of methyl ethanoate, the reaction should be performed at high temperatures with sufficient reflux time. The purity can be assessed through techniques such as:
- Distillation: To separate the ester from unreacted reagents and by-products.
- Analysis: Using methods like gas chromatography to determine the purity of the final product.