Solutions

Solubility - Henry’s LawSolubility - Henry’s Law

Solvation ReviewSolvation Review1. Explain the difference between a

homogeneous and a heterogeneous mixture.2. Give an example of a solute and an example

of a solvent.3. What states of matter can solutions consist

of?4. Explain the difference between soluble and

insoluble. Give an example of a substance soluble in water and a substance insoluble in water.

Solvation ReviewSolvation Review

5. Explain the terms miscible and immiscible and give an example of each.

6. What is the difference between a soluble substance and a miscible substance?

7. Describe the Tyndall Effect and the type of mixture it affects.

8. What are the three factors that affect the rate of solvation?

Temperature and SolubilityTemperature and Solubility As temperature is increased the

solubility of a solid solute will generally increase, with a few exceptions:

• As the temperature is increased, the solubility of a gas will decrease. At higher temperatures the gas molecules move much faster than they do a lower temperatures. So as a general rule gases are less soluble in hot liquids than in cool liquids.

That is why in the summer time there are a lot of fish kills in some estuaries due to the water being warmer and less oxygen available for the fish.

Pressure and Solubility – Henry’s Law

Henry’s Law – The solubility of any gas increases as the external pressure is increased

Pressure and Solubility – Henry’s Law

Example: carbonated beverages – once you “pop the top” on a Coke, the external pressure has been reduced, and the solubility of the CO2 goes down. This is why Coke goes “flat” in a very short amount of time.

Henry’s LawHenry’s Law

P = kC P= Pressure of a gas k= Henry’s Law Constant C=concentration of the gas

Calculate the amount, grams, of CO2 dissolved in 1.6 L of soda if the manufacturer uses a pressure of 2.4 atm of CO2 to carbonate the soda.

Henry’s Law Practice Henry’s Law Practice Problems Problems

This equation also describes Henry’s Law:S1 = S2 ‘s’ = solubility

P1 P2 ‘p’ = pressure

1.If 0.55 g of a gas dissolves in 1.0 L of water at 2 atm of pressure, how much will dissolve at 4.5 atm of pressure?

2. A gas has a solubility of 0.66 g/L at 10 atm of pressure. What is the pressure on a 1.0 L sample that contains 1.5 g of gas?

Henry’s Law Practice Henry’s Law Practice Problems IProblems IS1/P1 = S2/P2

3. If .68 g of a gas at 5 atm of pressure dissolves in 1.0 L of water at 25oC, how much will dissolve in 1.0 L of water at 8 atm of pressure and the same temperature?

4. A gas has a solubility of 1.46 g/L at 8 atm of pressure. What is the pressure of a 1.0 L sample that contains 2.7 g/L?

5. If 1.2 g of a gas at 6 atm of pressure dissolves in 1.0 L of water at 25oC, how much will dissolve in 1.0 L of water at 3 atm of pressure and the same temperature?