SolutionsSolutions

Solubility - Henry’s LawSolubility - Henry’s Law

Section 15.1Section 15.1

Solvation ReviewSolvation Review

1.1. Explain the difference between a Explain the difference between a homogeneous and a heterogeneous mixture.homogeneous and a heterogeneous mixture.

2.2. Give an example of a solute and an example Give an example of a solute and an example of a solvent.of a solvent.

3.3. What states of matter can solutions consist of?What states of matter can solutions consist of?

4.4. Explain the difference between soluble and Explain the difference between soluble and insoluble. Give an example of a substance insoluble. Give an example of a substance soluble in water and a substance insoluble in soluble in water and a substance insoluble in water.water.

Solvation ReviewSolvation Review

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

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

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

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

Temperature and SolubilityTemperature and Solubility As temperature is increased the solubility As temperature is increased the solubility

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

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

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

Pressure and Solubility – Henry’s Pressure and Solubility – Henry’s LawLaw

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

This equation describe Henry’s Law:This equation describe Henry’s Law:

S1S1 = = S2S2 ‘s’ = solubility ‘s’ = solubility

P1 P2 P1 P2 ‘p’ = pressure ‘p’ = pressure

Pressure and Solubility – Henry’s Pressure and Solubility – Henry’s LawLaw

Example: carbonated beverages – once you Example: carbonated beverages – once you “pop the top” on a Coke, the external pressure “pop the top” on a Coke, the external pressure has been reduced, and the solubility of the has been reduced, and the solubility of the COCO2 2 goes down. This is why Coke goes “flat” goes down. This is why Coke goes “flat”

in a very short amount of time.in a very short amount of time.

Henry’s Law Practice Problems IHenry’s Law Practice Problems I

S1/P1 = S2/P2

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 Problems IHenry’s Law Practice Problems 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?