Chapter 21

1. Chapter 21 Molar Mass Calculations Colligative Properties: Osmotic Pressure

3. 10.4g of molecular solute is dissolved in 164g of phenol. The freezing point of the solution is 36.3°C. What is the molecular mass? A

4. 10.4g of molecular solute is dissolved in 164g of phenol. The freezing point of the solution is 36.3°C. What is the molecular mass? A 102 g/mol

5. 10.4g of molecular solute is dissolved in 164g of phenol. The freezing point of the solution is 36.3°C. What is the molecular mass? A 102 g/mol

6. 10.4g of molecular solute is dissolved in 164g of phenol. The freezing point of the solution is 36.3°C. What is the molecular mass? A

7. 10.4g of molecular solute is dissolved in 164g of phenol. The freezing point of the solution is 36.3°C. What is the molecular mass? 102 g/mol

9. 2.53g of a molecular solute is dissolved in 63.5g of nitrobenzene. The freezing point of the solution is 3.40°C. Calculate the molecular mass? A

10. 2.53g of a molecular solute is dissolved in 63.5g of nitrobenzene. The freezing point of the solution is 3.40°C. Calculate the molecular mass? 116 g/mol A

11. 2.53g of a molecular solute is dissolved in 63.5g of nitrobenzene. The freezing point of the solution is 3.40°C. Calculate the molecular mass? 116 g/mol A

12. 2.53g of a molecular solute is dissolved in 63.5g of nitrobenzene. The freezing point of the solution is 3.40°C. Calculate the molecular mass? A

13. 2.53g of a molecular solute is dissolved in 63.5g of nitrobenzene. The freezing point of the solution is 3.40°C. Calculate the molecular mass? 116 g/mol

14. Semi-permeable Membrane • a partition that allows solvent particles to pass through but not solute particles

15. Osmosis • Osmosis: is when the solvent (normally water) flows from where there is a greater percentage of water to where there is a lesser percentage.

16. Other everyday examples of osmosis: • A cucumber placed in brine solution loses water and becomes a pickle. • A wilting flower placed in water will perk up because water enters by osmosis. • Eating large quantities of salty food can cause edema (swelling in the body caused by the accumulation of abnormally large amounts of fluid in the spaces between the body's cells or in the circulatory system).

17. Osmosis Examples

18. Can You Drink Too Much Water?

19. “Hold Your Wee for a Wii” • SACRAMENTO, Calif. - The coroner’s office has ruled that a woman who competed in a radio station’s contest to see how much water she could drink without going to the bathroom died of water intoxication. • Jennifer Strange, 28, was found dead Friday in her suburban Rancho Cordova home hours after taking part in the “Hold Your Wee for a Wii” contest in which KDND 107.9 promised a Nintendo Wii video game system for the winner. • “She said to one of our supervisors that she was on her way home and her head was hurting her real bad,” said Laura Rios, one of Strange’s co-workers at Radiological Associates of Sacramento. “She was crying and that was the last that anyone had heard from her.” Initially, contestants were handed eight-ounce bottles of water to drink every 15 minutes.

20. “Hold Your Wee for a Wii” • “They were small little half-pint bottles, so we thought it was going to be easy,” said fellow contestant James Ybarra of Woodland. “They told us if you don’t feel like you can do this, don’t put your health at risk.” • Ybarra said he quit after drinking five bottles. “My bladder couldn’t handle it anymore,” he added. • After he quit, he said, the remaining contestants, including Strange, were given even bigger bottles to drink. • “I was talking to her and she was a nice lady,” Ybarra said. “She was telling me about her family and her three kids and how she was doing it for kids.”

21. Water Intoxication • When too much water enters the body's cells, the tissues swell with the excess fluid. • Your cells try to maintain a specific osmotic pressure, so they try to regain the electrolyte balance by allowing water outside the cells to rush into the cells via osmosis. • Theoretically the cells could swell to the point of bursting. • From the cell's point of view, water intoxication produces the same effects as would result from drowning in fresh water. • Electrolyte imbalance and tissue swelling can cause an irregular heartbeat and allow fluid to enter the lungs. Swelling puts pressure on the brain and nerves, which can cause behaviors resembling alcohol intoxication. Swelling of brain tissue can cause seizures, coma and ultimately death.

22. Osmotic Pressure • OsmoticPressure (π) – the pressure required to prevent osmosis from occurring.

23. Reverse Osmosis

26. Osmotic Pressure (π) π = MRT

27. R values a

28. 75.9g of solute (gfm = 3722 g/mol) is dissolved to make a 1.10L solution at 25°C. What is the osmotic pressure? A

29. 75.9g of solute (gfm = 3722 g/mol) is dissolved to make a 1.10L solution at 25°C. What is the osmotic pressure? A 45.8kPa

30. 75.9g of solute (gfm = 3722 g/mol) is dissolved to make a 1.10L solution at 25°C. What is the osmotic pressure? A 45.8kPa

31. 75.9g of solute (gfm = 3722 g/mol) is dissolved to make a 1.10L solution at 25°C. What is the osmotic pressure? 45.8kPa

32. 12.7g of C12H22O11 is dissolved to make 150mL of solution at 30°C. What is the osmotic pressure? 625kPa

33. 12.7g of C12H22O11 is dissolved to make 150mL of solution at 30°C. What is the osmotic pressure? 625kPa

34. Homework • Worksheet: Molecular Mass and Osmosis