Multiple choice At what Temperature will 0.25 molal NaCl(aq) boil? Kb = 0.51oC kg mol-1 97.48oC 97.74oC 100.00oC 100.26oC 100.52oC Reveal answer Fill a bubble to check yourself D Correct answer Explanation Correct answer. Elevation in boiling point (ΔTb) = Kb x iNaCl x mNaCl = (0.51oC kg mol-1) x (2) x (0.25 mol/kg) = 0.26oC The boiling point of 0.25 molal NaCl = 100.00oC + 0.26oC = 100.26oC