Which of the following statement(s) is (are) wrong ?

Options

A. Methane cannot undergo addition reactions .
B. Ethanaol turns red litmus paper blue.
C. Acetaldehyde contains a ketone group as the only functional group.
D. All the isomers of a compound have the same properties.

Answer

To determine which statements are wrong, let's analyze each statement one by one:

1. **Statement A: Methane cannot undergo addition reaction.**
- Methane (CH₄) is a saturated hydrocarbon, meaning it contains only single bonds between carbon atoms. Addition reactions typically occur in unsaturated hydrocarbons, which have double or triple bonds. Since methane has no double bonds, it cannot undergo addition reactions.
- **Conclusion:** This statement is **true**.

2. **Statement B: Ethanol turns red litmus paper blue.**
- Ethanol (C₂H₅OH) is an alcohol and is generally neutral in nature, with a pH around 7. It does not have strong basic properties. Red litmus paper turns blue in the presence of a base, and since ethanol is neutral, it will not turn red litmus paper blue.
- **Conclusion:** This statement is **false**.

3. **Statement C: Acetaldehyde contains a ketone group.**
- Acetaldehyde (CH₃CHO) is an aldehyde, which has the functional group -CHO. A ketone has the functional group -C(=O)- between two carbon atoms. Since acetaldehyde is an aldehyde and does not contain a ketone group, this statement is incorrect.
- **Conclusion:** This statement is **false**.

4. **Statement D: All the isomers of a compound have the same property.**
- Isomers are compounds that have the same molecular formula but different structural arrangements. They can have different physical and chemical properties. Therefore, it is incorrect to say that all isomers have the same properties.
- **Conclusion:** This statement is **false**.

**Final Answer: The wrong statements are B, C, and D.**