Calculate the freezing point of a 2.0 m solution of NaCl in water. Remember that NaCl is an electrolyte. The normal freezing point of pure water is 0.00ºC. K_f (water)= -1.86ºC/m. A)-2.08ºC B)-3.72ºC C)-7.44ºC D)7.44ºC E)3.74ºC

Question

Quizplus · Accepted Answer

NaCl dissociates into Na+ and Cl- ions, effectively doubling the number of particles in solution. The freezing point depression is calculated using ΔTf = i * Kf * m, where i (van't Hoff factor) for NaCl is 2, Kf for water is -1.86ºC/m, and m is the molality (2.0 m). Thus, ΔTf = 2 * (-1.86ºC/m) * 2.0 m = -7.44ºC.

Calculate the Freezing Point of a 2