Terminal alkynes such as ethyne and 1-butyne will react with sodium metal.

Sodium metal is a highly reactive element and can undergo a variety of reactions with different compounds. In this case, we are given a list of compounds and we need to determine which one will react with sodium metal.

- Ethanol (Option A): Ethanol is an alcohol compound with the formula C2H5OH. It contains an -OH group, which makes it a potential candidate for reacting with sodium metal. When ethanol reacts with sodium metal, it undergoes a redox reaction, where the sodium is oxidized to sodium ethoxide (C2H5ONa) and hydrogen gas (H2) is released. This reaction can be represented as follows:

2Na + 2C2H5OH -> 2C2H5ONa + H2

- Ethanal (Option B): Ethanal is an aldehyde compound with the formula CH3CHO. It does not contain an -OH group and lacks the necessary functional group to react with sodium metal. Therefore, ethanal will not react with sodium metal.

- Ethene (Option C): Ethene is an alkene compound with the formula C2H4. It is a double-bonded hydrocarbon and does not contain any functional group that can react with sodium metal. Therefore, ethene will not react with sodium metal.

- Ethane (Option D): Ethane is an alkane compound with the formula C2H6. It is a saturated hydrocarbon and does not contain any functional group that can react with sodium metal. Therefore, ethane will not react with sodium metal.

In conclusion, the correct answer is option A, ethanol. Ethanol contains an -OH group, which enables it to react with sodium metal and undergo a redox reaction.