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The flow chart shows a series of steps involved in the production of ethyl butanoate - HSC - SSCE Chemistry - Question 20 - 2005 - Paper 1
Question 20
The flow chart shows a series of steps involved in the production of ethyl butanoate. Describe the chemistry and procedure involved in each of these steps, using di... show full transcript
Worked Solution & Example Answer:The flow chart shows a series of steps involved in the production of ethyl butanoate - HSC - SSCE Chemistry - Question 20 - 2005 - Paper 1
Step 1
Glucose to Mixture containing Ethanol
Answer
The initial step involves the fermentation of glucose to produce a mixture containing ethanol and carbon dioxide. The chemical equation for this process is:
ightarrow 2C_2H_5OH + 2CO_2$$ This typically occurs in the presence of yeast under anaerobic conditions at a temperature of about 30°C. The yeast ferments the glucose, converting it into ethanol and carbon dioxide.Step 2
Mixture containing Ethanol to Pure Ethanol
Answer
The next step is the distillation of the mixture to separate pure ethanol from the fermentation products. This is done by heating the mixture, as ethanol has a lower boiling point (78.37°C) compared to water (100°C). During distillation, the ethanol vaporizes and can be collected in a separate container, resulting in pure ethanol.
Step 3
Pure Ethanol to Ethyl Butanoate
Answer
The final step is the esterification of ethanol to form ethyl butanoate. This reaction involves ethanol reacting with butanoic acid in the presence of a catalyst, typically concentrated sulfuric acid. The chemical equation is:
This reaction is conducted under reflux conditions to ensure that it proceeds to completion. The product can be purified through simple distillation or extraction.