Question

What is the common name of Butan-1-ol ?

• A. Methanol
• B. n-Butyl alcohol
• C. n-Butanol n-Butyl alcohol
• D. Isobutyl alcohol

Hint:

The prefix "n-" stands for "normal," which designates a straight, unbranched carbon chain. Thus, the unbranched Butan-1-ol is commonly named n-butyl alcohol.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Alcohols are organic compounds containing one or more hydroxyl ($-$OH) groups.
Under IUPAC nomenclature, they are named with the suffix "-ol," while their common names are constructed by naming the alkyl group followed by the word "alcohol."

Step 3: Detailed Explanation:
Let us analyze the chemical structure of Butan-1-ol:
- The IUPAC name "Butan-1-ol" indicates a straight, unbranched four-carbon chain with a hydroxyl group attached to the first (terminal) carbon:
\[ CH_3-CH_2-CH_2-CH_2-OH \]
- The four-carbon straight-chain alkyl group is called the normal-butyl (or n-butyl) group.
- Therefore, the common name of this primary alcohol is constructed as:
\[ \text{n-Butyl alcohol} \]
Let us evaluate why the other options are incorrect:
- Methanol ($CH_3OH$): A single-carbon alcohol, commonly known as methyl alcohol.
- Isobutyl alcohol: An isomer of butanol with a branched carbon structure, namely 2-methylpropan-1-ol.
- Therefore, n-Butyl alcohol is the correct common name.

Step 4: Final Answer:
The common name of Butan-1-ol is n-Butyl alcohol.