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Acetone can be reduced, as shown - HSC - SSCE Chemistry - Question 33 - 2024 - Paper 1
Question 33
Acetone can be reduced, as shown. (a) Identify the shape around the central carbon atom in each molecule. (b) Explain how 13C NMR spectroscopy could be used to mon... show full transcript
Worked Solution & Example Answer:Acetone can be reduced, as shown - HSC - SSCE Chemistry - Question 33 - 2024 - Paper 1
Step 1
Identify the shape around the central carbon atom in each molecule.
Answer
The shape around the central carbon in the acetone molecule (reactant) is trigonal planar due to the presence of a carbonyl group (C=O), where the carbon is sp² hybridized. In the product (alcohol), the central carbon atom is tetrahedral, as it forms four single bonds with neighboring atoms (two hydrogens and an -OH group) and is sp³ hybridized.
Step 2
Explain how 13C NMR spectroscopy could be used to monitor the progress of this reaction.
Answer
In the 13C NMR spectrum of the reaction mixture at the start of the reaction, there will be two signals corresponding to the different carbon atoms (C=O and CH3) in the acetone molecule. As the reaction proceeds and acetone is reduced to alcohol, a new signal will appear in the 13C NMR spectrum, corresponding to the carbon atom in the -CH2OH group. This peak indicates the reduction has occurred, while the original peak for C=O will disappear as the reaction advances.