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7 Figure 12 shows the structure of the molecules of three organic compounds - Edexcel - GCSE Chemistry - Question 7 - 2023 - Paper 2
Question 7
7 Figure 12 shows the structure of the molecules of three organic compounds. (i) Each molecule in Figure 12 contains a different functional group. Circle the alken... show full transcript
Worked Solution & Example Answer:7 Figure 12 shows the structure of the molecules of three organic compounds - Edexcel - GCSE Chemistry - Question 7 - 2023 - Paper 2
Step 1
Step 2
Complete the equation for the reaction of propene with bromine by drawing the structure of a molecule of the product.
Answer
The reaction of propene with bromine involves the addition of bromine across the double bond. The product will be 1,2-dibromopropane, which can be represented as:
Br Br
| |
H₃C-C-C-H
| |
H H
This shows that each carbon involved in the double bond now has a bromine atom attached.
Step 3
Step 4
Describe how the fermentation of glucose is carried out and how the dilute solution of ethanol produced can then be processed to form a concentrated solution of ethanol.
Answer
Fermentation of Glucose
To carry out fermentation, glucose (C₆H₁₂O₆) is dissolved in water to create a solution. Yeast is then added to this solution, which contains enzymes that break down the sugar into ethanol (C₂H₅OH) and carbon dioxide (CO₂) under anaerobic conditions (absence of oxygen), at a temperature of approximately 25-40°C.
Processing the Dilute Solution
Once fermentation has occurred, the dilute solution of ethanol can be concentrated through the process of distillation:
- Distillation Setup: The solution is placed in a distillation flask.
- Heating: The flask is heated to boil the solution, causing ethanol to vaporize (as it has a lower boiling point than water).
- Condensation: The vapor rises and passes through a condenser, where it cools and turns back into liquid.
- Collection: The concentrated ethanol is collected in a separate container, while the water remains in the distillation flask.
This method allows for the efficient separation of ethanol from water, resulting in a concentrated ethanol solution.