Answer to Question #75164 in General Chemistry for Chloe Lozano

Question

Calculate the freezing point of a solution formed when 55.0 g of NH3 are mixed with 820.0 g of water. (NOTE: NH3 does not dissolve into multiple ions; each molecule dissolves as an individual whole. Also, the Kf of water is 1.86 oC/m.)

A. –14.3 oC
B. –7.15 oC
C. 0.0 oC
D. 7.15 oC
E. 14.3 oC

Answer 1

Solution:
ΔT = Kf x molality = 1.86 0

C/m x 55.0 g / 17,031 g/mol / 0.8200 kg = 7.3 0
C.

Answer: B. -7.15 C.