Question

PLEASE ANSWER ALL PARTS AND SHOW THE WORK CLEARLY.

2. A solution containing 2.00 g of an unknown substance in 50.0 g of cyclohexane freezes at 1.05°C. The normal freezing point of cyclohexane is 6.60°C and Kf = 20.4 °C/m. Both substances are molecular.

a. What is the value of i? __________

b. Calculate the molality of the solution using ∆T = Kf • m • i. Show all work.

c. The units of molality are moles/kg. Moles of what over kilograms of what? Be more specific than solute and solvent – label the compounds!

Moles of ________ over kilograms of _______

d. How many moles of the unknown substance are in this solution? Show all work.

e. What is the molar mass of the unknown substance? Show all work