The incorrect combination of names for isomeric alcohols with molecular formula `C_(4)H_(10)O` is/are

Options

A. tert-butanol and 2-methylpropan-2-ol
B. tert-butanol and 1, 1-dimethylethan -1-ol
C. n-butanol and butan -1-ol
D. iso-butyl alcohol and 2-methylpropan-1-ol

Answer

To solve the question regarding the incorrect combination of names for isomeric alcohols with the molecular formula \( C_4H_{10}O \), we need to identify the possible isomers of alcohols that can be formed with this molecular formula and their corresponding names.

### Step-by-Step Solution:

1. **Identify the Molecular Formula**:
The molecular formula given is \( C_4H_{10}O \). This indicates that we are dealing with alcohols that have four carbon atoms.

2. **Draw the Structural Isomers**:
We can have several structural isomers for alcohols with the formula \( C_4H_{10}O \):
- **Butan-1-ol**: \( CH_3-CH_2-CH_2-CH_2OH \)
- **Butan-2-ol**: \( CH_3-CH(OH)-CH_2-CH_3 \) (secondary alcohol)
- **Isobutyl alcohol (2-methylpropan-1-ol)**: \( (CH_3)_2CH-CH_2OH \)
- **Tert-butyl alcohol (2-methylpropan-2-ol)**: \( (CH_3)_3C-OH \)

3. **List the Names of the Isomers**:
- Butan-1-ol (also known as n-butanol)
- Butan-2-ol (secondary butanol)
- Isobutyl alcohol (2-methylpropan-1-ol)
- Tert-butyl alcohol (2-methylpropan-2-ol)

4. **Check the Given Combinations**:
Now we need to check the combinations provided in the question to identify which ones are incorrect:
- **Option 1**: 3rd butanol and 2-methylpropane-2-ol (this is actually tert-butyl alcohol)
- **Option 2**: n-butanol and butan-1-ol (this is a repetition and thus incorrect)
- **Option 3**: Isobutyl alcohol and 2-methylpropan-1-ol (this is correct)
- **Option 4**: Butan-2-ol and 2-methylpropan-2-ol (this is correct)

5. **Identify the Incorrect Combination**:
From the analysis, the incorrect combination is found in **Option 2**: n-butanol and butan-1-ol are the same compound.

### Final Answer:
The incorrect combination of names for isomeric alcohols with the molecular formula \( C_4H_{10}O \) is **Option 2**: n-butanol and butan-1-ol.