If one salt lowers melting point farther than another, hypothesize why this is happening, thinking about the molecular difference between NaCl and CaCl2.

Answer 1

Lowering the freezing point is a colligative property, meaning that it depends on the number of particles present in solution. If the NaCl and CaCl2 are present at the same molal concentration, then NaCl will provide 2 particles and CaCl2 will provide 3 particles, so the freezing point depression will be greater for CaCl2 than for NaCl.