Question

On adding 2 mL acetic acid to 2 mL of water in a test tube, it was observed that:

Answer 1

:Hint: Acetic acid is an organic acid (carboxylic acid) and it consists of a methyl group attached to a carboxylic acid functional group. The name of the compound according to IUPAC nomenclature is ethanoic acid; ethan- representing a two carbon chain with a single bond and –oic acid representing the functional group carboxylic acid.

Complete answer:
We know that acetic acid or ethanoic acid is an organic acid. The carbon atom in the functional group is attached to two oxygen atoms of which one oxygen is bonded to a hydrogen atom as well. Due to high electronegativity of oxygen atoms, the hydrogen oxygen bond is highly polar. Additionally, the presence of another oxygen atom bonded to the carbon atom increases the polarity of the bond. Hence the hydrogen present in this group is acidic and the molecule is highly polar.
We know that like dissolves like, that means, polar substances are soluble in polar solvents and non- polar substances in non- polar solvents. Water is a polar solvent due to high electronegativity difference between hydrogen and oxygen. Similarly acetic acid is also a polar compound. Thus, it is completely miscible in water.
Hence, when 2 mL acetic acid to 2 mL of water in a test tube, we will observe a clear transparent solution as acetic acid is soluble in water

Note:
The miscibility of the two solutions also increases due to intermolecular hydrogen bonding. Both the molecules have hydrogen atoms bonded to oxygen atoms and thus form hydrogen bonds, thus, increasing the stability.