Solution Stoichiometry

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Slide 1

Solutions

Slide 2

Solute

A solute is the dissolved substance in a solution.

A solvent is the dissolving medium in a solution.

Solvent

Salt in salt water

Sugar in soda drinks

Carbon dioxide in soda drinks

Water in salt water

Water in soda

Slide 3

“Like Dissolves Like”

Polar and ionic solutes dissolve best in polar solvents

Nonpolar solutes dissolve best in nonpolar solvents

Slide 4

Solubility Trends

The solubility of MOST solids increases with temperature.

The rate at which solids dissolve increases with increasing surface area of the solid.

The solubility of gases decreases with increases in temperature.

The solubility of gases increases with the pressure above the solution.

Slide 5

Therefore…

Solids tend to dissolve best when:

Heated

Stirred

Ground into small particles

Gases tend to dissolve best when:

The solution is cold

Pressure is high

Slide 6

Solubility Chart

Slide 7

Saturation of Solutions

A solution that contains the maximum amount of solute that may be dissolved under existing conditions is saturated.

A solution that contains less solute than a saturated solution under existing conditions is unsaturated.

A solution that contains more dissolved solute than a saturated solution under the same conditions is supersaturated.

Slide 8

Definition of Electrolytes and Nonelectrolytes

An electrolyte is:

A substance whose aqueous solution conducts an electric current.

A nonelectrolyte is:

A substance whose aqueous solution does not conduct an electric current.

Slide 9

Electrolytes vs. Nonelectrolytes

The ammeter measures the flow of electrons (current)

through the circuit.

If the ammeter measures a current, and the bulb

glows, then the solution conducts.

If the ammeter fails to measure a current, and the

bulb does not glow, the solution is non-conducting.

Slide 10

Pure water

Tap water

Sugar solution

Sodium chloride solution