Question

What happens when a small piece of sodium is dropped into ethanol.

Answer 1

Hint: The molecular formula of ethanol is \[{C_2}{H_6}O\], indicating that ethanol contains two carbons and an oxygen. However, the structural formula of ethanol, \[C{H_3}C{H_2}OH\], provides a little more detail, and indicates that there is an hydroxyl group $\left( { - OH} \right)$ at the end of the 2-carbon chain

Complete answer:
If a small piece of sodium is dropped into ethanol, it reacts steadily to give off bubbles of hydrogen gas and leaves a colorless solution of sodium ethoxide: \[C{H_3}C{H_2}ONa\]. The anion component is an alkoxide.
 \[2C{H_3}C{H_2}OH\left( l \right) + 2Na\left( s \right) \to 2C{H_3}C{H_2}{O^ - }\left( {aq} \right) + 2N{a^ + }\left( {aq} \right) + {H_2}\left( g \right)\]
If the solution is evaporated carefully to dryness, then sodium ethoxide ( \[C{H_3}C{H_2}ONa\]) is left behind as a white solid. Although initially this appears as something new and complicated, in fact, it is exactly the same (apart from being a more gentle reaction) as the reaction between sodium and water - something you have probably known about for years.
\[2{H_2}O\left( l \right) + 2Na\left( s \right) \to 2O{H^ - }\left( {aq} \right) + 2N{a^ + }\left( {aq} \right) + {H_2}\left( g \right)\]
If you spill some sodium on the bench or have a small amount left over from a reaction you cannot simply dispose of it in the sink. It tends to react explosively with the water - and comes flying back out at you again! It reacts much more gently with ethanol. Ethanol is, therefore, used to dissolve small quantities of waste sodium.

Note:
When sodium reacts with water, the reaction is exothermic. During the reaction, the sodium metal may well become so hot that it catches fire and burns with a characteristic orange color. When a small piece of sodium is dropped into ethanol, it reacts strongly and produces bubbles of gas. Phenols and alcohols react with active metals to produce corresponding alkoxides or phenoxides and hydrogen.