Chapter 7 Solutions 7.3 Solubility Copyright © 2005 by Pearson Education, Inc. Publishing as Benjamin Cummings

Solubility Solubility is the maximum amount of solute that dissolves in a specific amount of solvent. expressed as grams of solute in 100 grams of solvent water. g of solute 100 g water

Unsaturated Solutions contain less than the maximum amount of solute. can dissolve more solute. Dissolved solute Copyright © 2005 by Pearson Education, Inc. Publishing as Benjamin Cummings

Saturated Solutions Saturated solutions contain the maximum amount of solute that can dissolve. have undissolved solute at the bottom of the container. Copyright © 2005 by Pearson Education, Inc. Publishing as Benjamin Cummings

Learning Check At 40C, the solubility of KBr is 80 g/100 g H2O. Identify the following solutions as either 1) saturated or (2) unsaturated. Explain. A. 60 g KBr added to 100 g of water at 40C. B. 200 g KBr added to 200 g of water at 40C. C. 25 g KBr added to 50 g of water at 40C.

Solution A. 2 Amount of 60 g KBr/100 g water is less than the solubility of 80 g KBr/100 g water. B. 1 In 100 g of water, 100 g KBr exceeds the solubility of 80 g KBr water at 40C. C. 2 This is the same as 50 g KBr in 100 g of water, which is less than the solubility of 80 g KBr/100 g water at 40C.

Effect of Temperature on Solubility Depends on temperature. Of most solids increases as temperature increases. Of gases decreases as temperature increases.

Learning Check A. Why could a bottle of carbonated drink possibly burst (explode) when it is left out in the hot sun ? B. Why do fish die in water that is too warm?

Solution A. The pressure in a bottle increases as the gas leaves solution as it becomes less soluble at high temperatures. As pressure increases, the bottle could burst. B. Because O2 gas is less soluble in warm water, fish cannot obtain the amount of O2 required for their survival.

Solubility and Pressure Henry’s Law states the solubility of a gas in a liquid is directly related to the pressure of that gas above the liquid. at higher pressures, more gas molecules dissolve in the liquid.