To rank the given compounds in order of polarity, we need to consider the functional groups and molecular structures of each compound.
First, let’s analyze each compound:
- 3-nitrobenzoic acid: This compound contains a carboxylic acid group (-COOH) which is highly polar. The presence of the nitro group (-NO2) further increases its polarity due to its strong electron-withdrawing effect. Therefore, 3-nitrobenzoic acid is very polar.
- 2-naphthol: This compound has a hydroxyl group (-OH) that also contributes to its polarity, but it doesn’t have the same level of polarity as the carboxylic acid found in 3-nitrobenzoic acid. The naphthalene moiety adds some non-polar characteristics, making it less polar than 3-nitrobenzoic acid, but still more polar than purely non-polar compounds.
- 4-dimethoxybenzene: This compound consists of two methoxy groups (-OCH3) attached to a benzene ring. While methoxy groups can have some electron-donating effects, 4-dimethoxybenzene is still relatively non-polar compared to the other two compounds because it lacks highly polar functional groups like -COOH or -OH.
Based on this analysis, we can rank the compounds from most to least polar:
- 3-nitrobenzoic acid
- 2-naphthol
- 4-dimethoxybenzene
This ranking reflects the influence of functional groups on the overall polarity of the compounds, with 3-nitrobenzoic acid being the most polar due to the presence of both a carboxylic acid and a nitro group, followed by 2-naphthol with its hydroxyl group, and finally 4-dimethoxybenzene, which is largely non-polar.