Draw Lewis structures and condensed structural formulas for the four alcohols with the molecular formula C4H10O. Classify each alcohol as primary, secondary, or tertiary. (Hint: First consider the connectivity of the four carbon atoms; they can be bonded either four in a chain or three in a chain with the fourth carbon as a branch on the middle carbon. Then consider the points at which the iOH group can be bonded to each carbon chain.)
The Correct Answer and Explanation is :
The molecular formula C4H10O corresponds to four possible alcohols. These alcohols differ based on the arrangement of the carbon atoms and the location of the hydroxyl group (-OH). Here’s how we can break it down:
1. Butan-1-ol (1-Butanol)
- Lewis structure: The hydroxyl group (-OH) is attached to the first carbon atom in a straight chain. The other carbon atoms are bonded to hydrogens to satisfy the valency of carbon (4 bonds per carbon).
- Condensed formula: CH₃CH₂CH₂OH
- Classification: Primary alcohol (The -OH group is attached to a primary carbon, which is bonded to one other carbon atom).
2. Butan-2-ol (2-Butanol)
- Lewis structure: The hydroxyl group is attached to the second carbon in a straight chain, and the other carbons are bonded to hydrogens.
- Condensed formula: CH₃CH(OH)CH₂CH₃
- Classification: Secondary alcohol (The -OH group is attached to a secondary carbon, which is bonded to two other carbon atoms).
3. 2-Methylpropan-1-ol (Isobutanol)
- Lewis structure: The structure features a branched chain with a -OH group attached to the first carbon in the chain. The second and third carbons are attached as branches.
- Condensed formula: (CH₃)₂CHCH₂OH
- Classification: Primary alcohol (The -OH group is attached to a primary carbon).
4. 2-Methylpropan-2-ol (tert-Butanol)
- Lewis structure: The -OH group is attached to the second carbon of a branched chain, which is also bonded to three other carbons.
- Condensed formula: (CH₃)₃COH
- Classification: Tertiary alcohol (The -OH group is attached to a tertiary carbon, which is bonded to three other carbon atoms).
Explanation
- Butan-1-ol and Isobutanol are classified as primary alcohols because the -OH group is attached to a carbon atom that is only bonded to one other carbon.
- Butan-2-ol is a secondary alcohol because the -OH group is attached to a carbon bonded to two other carbon atoms.
- Tert-Butanol is a tertiary alcohol because the -OH group is attached to a carbon that is bonded to three other carbon atoms.
I will now generate the Lewis structures and condensed structural formulas for you.
Here are the Lewis structures and condensed formulas for the four alcohols with the molecular formula C4H10O:
- Butan-1-ol (1-Butanol): Primary alcohol with the hydroxyl group attached to the first carbon.
- Butan-2-ol (2-Butanol): Secondary alcohol with the hydroxyl group attached to the second carbon.
- 2-Methylpropan-1-ol (Isobutanol): Primary alcohol with the hydroxyl group attached to the first carbon of a branched chain.
- 2-Methylpropan-2-ol (tert-Butanol): Tertiary alcohol with the hydroxyl group attached to the second carbon in a branched chain.
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