Aniline point test of an oil qualitatively indicates the __________ content of an oil.

Definition: The aniline point of an oil is the minimum temperature at which the oil is completely miscible with an equal volume of aniline.

Purpose of test: It is used as a qualitative measure of the aromatic content in petroleum oils.

Reason: Aromatic hydrocarbons mix more readily with aniline than paraffinic hydrocarbons, resulting in a lower aniline point for oils with higher aromatic content. Conversely, oils rich in paraffins have higher aniline points.

Conclusion: The aniline point test gives an indication of the aromatic content of an oil — lower aniline point means higher aromatic content, and higher aniline point means lower aromatic content.