0.1 m aqueous solution of NaCl (assumed fully ionised) has a freezing-point depression closest to (K_f = 1.86 K kg/mol)

1. For an electrolyte ΔT_f = i · K_f · m where i is the van't Hoff factor. 2. For fully dissociated NaCl, i = 2. 3. ΔT_f = 2 × 1.86 × 0.1 = 0.372 K. _Source: Maharashtra Balbharati Std XII Chemistry, Ch 2 "Solutions" §2.8_