C. Investigating the Cause of the Fish Kill

Focus: Water as a solvent

How are solutions described?

How do solutions behave?

What are the possibilities?

C.1 Solubility of Solids in H2O

• In a solution, the solvent is the dissolving agent and the solute is the dissolved substance

-solvent is doing the dissolving-solute is being dissolved

C.1 Solubility of Solids in H2OSOLIDSKool-aid in waterSalt in waterSugar in water

GASESCarbon Dioxide in water (carbonated)Dissolved Oxygen in water (DO)

LIQUIDSFood coloringVinegarEthanol

• The maximum amount of a substance that will dissolve in a specific amount of water is called solubility.

C.1 Solubility of Solids in H2O

C.1 Solubility of Solids in H2OHow much salt will dissolve in 100 g of water at room temperature?

Solubility of NaCl can be expressed in a solubility curve (graph).

~40g of salt dissolves in 100ml ofwater at 22°C

~200g of sugar dissolves in 100mlof water at 22°C

How much potassium nitrate dissolves in 100g of water at 50°C?

How much potassium nitrate dissolves in 100g of water at 10°C?

How much potassium nitrate would recrystallize if the solution cooled from 50 to 10°C?

Which substance is more soluble at 0°C, 20°C, 70°C, 100°C?

For which substances does solubility decrease as temperature increases?

At what temperature will 50g of NH4Cl reach saturation?

C.1 Solubility of Solids in H2O

Saturated solution: The solvent contains as much dissolved solute as it can possibly hold at that temperature

Unsaturated solution: The solvent contains less than the solubility at that temperature.

Supersaturated: The solvent contains more than the solubility at that temperature.

*Be able to describe solutions on graph using these terms.