In the discussion, a user raises a question about the Rf values of maleic acid and fumaric acid, noting that maleic acid has an Rf of 1.4 and fumaric acid has an Rf of 4.5. There is confusion regarding the interpretation of Rf values, as it is typically reported within a 0 to 1 range, suggesting that the values provided may be incorrect. It is clarified that Rf is not a property of a solvent but rather a characteristic of the solvent-substance-stationary phase combination. Additionally, it is noted that neither maleic nor fumaric acid is a liquid at room temperature, indicating they are not solvents in this context. The discussion concludes with an explanation of polarity, stating that fumaric acid has lesser polarity than maleic acid due to the cancellation of polarities from its two carboxylic acid groups, while maleic acid retains a higher overall polarity.