Answer to Question #202629 in General Chemistry for joooosh

Question

Phytonadione, or more known as vitamin K1 , serves important roles in blood clotting mechanisms, bone health, and even bone health. When 0.368 g is dissolved in 12.0 g of camphor, the freezing point is lowered by 2.45 °C.

Answer 1

Step 1: Calculate the freezing point depression of benzene.

Tf = (Freezing point of pure solvent) - (Freezing point of solution)

(5.5 ^oC) - (2.8 ^oC) = 2.7 ^oC

Step 2 : Calculate the molal concentration of the solution

molality = moles of solute / kg of solvent

moles of naphthalene = (1.60 g) (1 mol / 128 g) = 0.0125 mol naphthalene

molality of solution = (0.0125 mol) / (0.0200 kg) = 0.625 m

Step 3: Calculate K_f of the solution.

Tf = (K_f) (m)

(2.7 ^oC) = (K_f) (0.625 m)

K_f = 4.3 ^oC/m