Question

part f
summarize your findings, and compare the odor, flammability, density, ability to dissolve sugar, and boiling point of each of the fractions and of the original mixture.

• what do you conclude about the composition of the fractions?
• can you identify the substances in the original mixture? (see table 3.2 on page 66.)
• what other tests might you run to help identify these substances?
• what do you think would happen if you were to fractionally distill each of the fractions separately?

Explanation:

This problem involves analyzing the properties (odor, flammability, density, solubility of sugar, boiling point) of fractions from a mixture and the original mixture, then drawing conclusions about composition, identifying substances, proposing further tests, and predicting the outcome of re - fractionating the fractions. These tasks are related to the study of matter and its properties, which falls under the subfield of Chemistry (a subfield of Natural Science). To solve it, one would first recall the properties of common substances (from Table 3.2 as referenced). For example, if a fraction has a certain boiling point, odor, and solubility, we can compare it to known substances. When analyzing the composition of fractions, if the properties of a fraction are more uniform than the original mixture, it suggests that the fractionation process has separated components. To identify substances, we match the measured properties (like boiling point) to those in the table. For further tests, we could consider tests like freezing point determination, conductivity tests (to see if the substance is an electrolyte), or chemical reaction tests (e.g., reacting with specific reagents). For the fractionation of fractions, if a fraction is a pure substance (or a nearly pure substance), re - fractionating it would not change its properties (like boiling point) significantly; if it's still a mixture, re - fractionation would further separate components.

Answer:

The problem is related to the subfield of Chemistry (Natural Science). To solve it:

1. Composition of Fractions: If the properties (odor, flammability, density, sugar solubility, boiling point) of a fraction are more consistent than the original mixture, the fraction likely contains a more concentrated or pure component. For example, if a fraction has a narrow boiling point range, it may be a pure substance or a mixture of substances with very similar properties.
2. Identifying Substances: By comparing the measured properties (e.g., boiling point) of the fractions and the original mixture to the properties of known substances (from Table 3.2), we can identify the substances. For instance, if a fraction has a boiling point of 78°C and is flammable, it could be ethanol.
3. Other Tests: Tests like freezing point determination (to find the freezing point depression, which can indicate molar mass if it's a solute in a solvent), conductivity tests (to check if the substance is ionic or covalent), or chemical tests (e.g., reacting with acid - base indicators or specific reactants) can help identify substances.
4. Refractionating Fractions: If a fraction is a pure substance (e.g., a single compound), re - fractionating it will not change its boiling point (it will boil at a constant temperature). If the fraction is still a mixture, re - fractionation will further separate the components, resulting in fractions with more uniform properties.