Distillation involves the separation of compounds by taking advantage of their different boiling points. Mixtures with similar boiling points would not be adequately separated using distillation.

A racemic mixture is a mixture of enantiomers, which have identical boiling points. As a result, distillation would not be effective for separating a racemic mixture.

Diastereomers will have differing physical properties and can be separated by boiling point. Larger alkane chains result in higher boiling points, allowing separation of different sized alcohols by distillation. Polar compounds will have greater intermolecular forces, generally leading to higher boiling points, and allowing them to be separated from nonpolar compounds.

During recrystallization, a compound is separated from impurities based on differences in solubility in a given solvent.

To correctly recrystallize a compound, the correct solvent must be used. Good solvents are ones in which the product is slightly soluble and impurities are completely soluble. Additionally, the temperature plays a large role in this process, as you must decrease the temperature of the solution to decrease the solubility of desired product enough to have the product crash out as a solid.

Recrystallization is the purification of a product based on differences in solubility. The desired compound is placed in a solvent in which it is just barely soluble, but in which impurities are highly soluble. The mixture is heated to melt the desired compound, creating a homogeneous solution. The solution is then cooled, allowing the desired compound to slowly precipitate out of solution due to its low solubility.

For the purest product, the most important aspect is to let your product cool down as slowly as possible so that the crystal structure contains the least amount of impurities. Melting the product slowly or quickly will not affect the purity of the product, and thus a faster melting stage will allow for the quickest and purest product formation.

When choosing an appropriate solvent for recrystallization, it is crucial that the crystals do not dissolve at room temperature and do dissolve when the sample is heated. For this reason, we cannot say without further information whether or not this solvent will be useful. For example, the researcher could heat the sample to the boiling point of the solvent only to discover that his crystals still do not dissolve. The researcher first has to heat the sample and observe the effect on the crystals to know whether or not this solvent is useful.

Paper chromatography is used to separate compounds based on differing polarities. Polar compounds will move more slowly, because they have a higher affinity for the polar paper strip. As a result, they will stop at a lower spot on the paper compared to the nonpolar compounds, which will end up near the top of the strip. In some cases, a non-polar paper can be used, but polar paper is standard and should be assumed if no other information is given.

In paper chromatography, the most nonpolar compound will travel the farthest on the paper strip. The compound that travels the farthest will have the largest R_f  factor. Hexane is nonpolar, so it will travel the farthest and have the largest R_f factor out of these possible compounds.

The greatest R_f value is associated with the least polar mixture component. This is because the component with the greatest solubility in the mobile phase will be pulled by the solvent upwards, and will not be attracted to the polar stationary phase (the paper). More polar solutes will travel more slowly due to attractive forces with the polar stationary phase. Out of all of the answer choices, benzene is least polar and is therefore the correct answer.

The value is proportional to the affinity of the solute to the solvent. The solvent acts as the mobile phase along a polar paper stationary phase. Polar compounds will interact more with the paper, travelling slowly, while nonpolar compounds will interact more with the solvent, travelling more quickly.

A large  value represents a large proclivity for the mobile solvent in the experiment. Because we are using ether, a non-polar solvent, we would expect non-polar compounds to travel the farthest on our plate. Of the answer choices, alkanes are the least polar and would thus travel farthest into the mobile phase of the four functional groups. A polar functional group, like a halide, will interact more in the stationary phase, and will thus has a significantly smaller  value. 

Generally, extraction is the best means of separating two solutes based on polarity. This technique allows separation based on solubility in two different solvents, which separate based on polarity.

Extraction, however, is not offered as an answer. The next best option would be thin layer chromatography. In this process, a polar stationary phase is introduced to a nonpolar solvent. Solutes are placed on the stationary phase. The nonpolar solvent acts as the mobile phase. Nonpolar solvents interact more with the mobile solvent, travelling quickly along the polar stationary phase, while polar solutes are attracted to the stationary phase and travel more slowly. This property allows for separation based on polarity.

Ion exchange chromatography is used to separate compounds with different charges, not necessarily differing polarities. Mass spectroscopy will identify compounds based on mass, and distillation will allow for separation based on differences in boiling point and vapor pressure.

The stationary phase in chromatography is typically attracted to the more polar compounds in a solution, while the mobile phase carried the nonpolar compounds. As a result, more polar compounds will move a shorter distance, resulting in a lower R_f factor. Glucose is a very polar molecule, and would move a shorter distance compared to the other options.