Final answer:
To separate sugar and salt, leverage their different solubilities in water with temperature variation for dissolution and recrystallization. Use filtration and evaporation methods to physically separate them.
Step-by-step explanation:
To separate sugar and salt, a student can utilize the fact that sugar and salt have different solubilities in water at various temperatures. Salt is highly soluble in water but sugar's solubility increases with temperature. Thus, adding both to water and heating dssolves the sugar but leaves much of the salt undissolved. By carefully cooling the solution, the sugar stays dissolved while salt crystallizes, which can be removed through filtration. The resulting solution can then be evaporated to recover the dissolved sugar.
During this process, the distinctive properties of salt and sugar are utilized. Sugar (C12H22O11), a molecular compound, does not dissociate into ions when dissolved and has a high solubility in hot water. Conversely, salt (NaCl), an ionic compound, dissociates into sodium and chloride ions in solution but can be recrystallized by cooling the saturated solution.
In summary, physical properties like solubility and crystallization allow physical separation methods to be applied effectively in the separation of mixtures like sugar and salt without altering their chemical compositions.