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Ethanol is made by fermentation of a carbohydrate dissolved in water, in the presence of yeast - Edexcel - GCSE Chemistry - Question 4 - 2019 - Paper 1
Question 4
Ethanol is made by fermentation of a carbohydrate dissolved in water, in the presence of yeast. The reaction is carried out at 30 °C. Explain why the reaction is c... show full transcript
Worked Solution & Example Answer:Ethanol is made by fermentation of a carbohydrate dissolved in water, in the presence of yeast - Edexcel - GCSE Chemistry - Question 4 - 2019 - Paper 1
Step 1
Explain why the reaction is carried out at a temperature of 30 °C rather than at a temperature of 80 °C.
Answer
The fermentation process requires specific enzymes provided by yeast, which function optimally at around 30 °C. At higher temperatures, such as 80 °C, these enzymes can become denatured, rendering them ineffective and ultimately stopping the fermentation process. Therefore, to ensure the enzymes remain active and effective, the reaction is maintained at 30 °C.
Step 2
Step 3
Draw the structure of a molecule of ethanoic acid, CH₃COOH, showing all covalent bonds.
Answer
The structure of ethanoic acid is:
O
||
H--C--O--H
|
C
/
H H
In this structure, all covalent bonds are depicted clearly, with hydrogen atoms attached to carbon and the functional carboxylic acid group (-COOH) shown.