During the purification of a crude sample of aspirin (135 ∘C135\ ^\circ\text{C}135 ∘C) via recrystallisation, a student performs the following sequential steps:
Which statement correctly explains the scientific rationale for the specified step?
The hot filtration (Step 2) is performed to remove soluble impurities from the mixture before crystallization begins.
Dissolving the crude aspirin in the minimum volume of hot ethanol (Step 1) ensures the solution is saturated, maximising the mass of crystals obtained on cooling.
Washing the aspirin crystals on the Büchner funnel (Step 4) with warm ethanol ensures that any remaining impurities are dissolved and washed through the filter.
Plunging the hot filtrate directly into an ice bath (Step 3) ensures rapid crystal growth, which prevents impurities from being trapped within the crystal lattice.
