More%20Colligative%20Answers

More%20Colligative%20Answers - 2 S dissolved in a solution...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
More Colligative Properties 1. Given the freezing point of camphor is 178.75 and k f = 37.7 C/m, what is the boiling point if 75 g of CF 4 is added to 625 g of camphor? ΔT f = 37.7 * (0.85218 mol / 0.625 kg) = 51.40 T f = 178.75 - 51.40 = 127.35 2. The vapor pressure of a sample of benzene (C 6 H 6 ) is 125 torr at a certain temperature. When an unknown amount of C 6 H 12 O is added to 1050 g of benzene, the vapor pressure becomes 113 torr. Solve for the mass of C 6 H 12 O that is added. Solute: C 6 H 12 O, unknown amount Solvent: C 6 H 6 , 1050 g = 13.44 mol 113 = χ solv 125 χ solv = 0.904 = 13.44 / (13.44 + mol(C 6 H 12 O)) 0.904(13.44 + mol(C 6 H 12 O)) = 13.44 (13.44 + mol(C 6 H 12 O)) = 14.867 mol(C 6 H 12 O) = 1.427 mol = 142.98 grams
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
3. Solve for the osmotic pressure of a solution that has 25 g of Na
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 2 S dissolved in a solution of 1.50 L. 25 g Na 2 S = 0.3203 moles of Na 2 S = 0.9609 moles of ions M = 0.9609 moles / 1.50 L = 0.6406 M **Oops, I forgot to give a temperature, let's go with 25 Celsius** = 0.6406 * 0.0821 * 298.15 = 15.68 atm 4. Find the boiling point of the solution in question 3, given that the solvent is water, the density of the solution is 1.05 g/mL and the k b 0.515 C/m. solute, Na 2 S has 0.9609 moles of ions present solvent, water, unknown mass solution, 1.50 L = 1500 mL * 1.05 g/mL = 1575 grams Mass Solvent = Mass Solution - Mass Solute = 1575 g - 25 g = 1550 g molality = 0.9609 moles / 1.550 kg = 0.6199 T b = 0.515 * 0.6199 = 0.319 T b = 100.3 Celsius...
View Full Document

Page1 / 2

More%20Colligative%20Answers - 2 S dissolved in a solution...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online