A student dissolves 15 g of sodium chloride in 100 mL of water to form a clear, homogeneous solution. The student wants to recover the dissolved salt as pure, dry crystals without needing to collect the water. Which experimental procedure should the student follow, and which scientific principle explains its success?
- A) Heat the mixture in an evaporating dish until all water vaporizes; the liquid solvent has a significantly lower boiling point than the non-volatile solid solute, leaving the salt behind.
- B) Pass the mixture through a filter paper cone in a funnel; the solid salt particles are too large to pass through the pores of the filter paper.
- C) Allow the mixture to stand undisturbed in a beaker for several hours so that the denser salt settles to the bottom, then decant the upper liquid layer.
- D) Cool the mixture to lower temperatures; cooling accelerates the evaporation of water while causing the dissolved salt to solidify into an immiscible liquid layer.
