Solubility

Dissolving• Particles of the solute move

into the solvent

Crystallization• After a while, solute particles

which are already dissolved begin to collide with un-dissolved particles, returning them to solid

• As more particles dissolve, more particles crystallize until EQUILIBRIUM is reached

Equilibrium• The rate where particles

dissolve equals the rate where particles crystallize. • When equilibrium is reached

un-dissolved solute remains visible no matter what

Saturated Solution• no more solute will dissolve• max amount of solute at a

particular temperature• particles dissolve and crystallize

but the concentration remains the same

Supersaturated Solution

• a substance that has been heated to dissolve additional solute and then carefully cooled (more than saturated)

Qualitative Solubility• relative

solubility in terms of soluble, low solubility or insoluble

Quantitative Solubility• The concentration of a solute

in a saturated solution at a given temperature• # of moles of solute needed to

form 1 litre of saturated solution at a specified temp.

• Solubility of a saturated solution- aka molarity

- aka concentration

Example

• A saturated solution produced by dissolveing hydrogen chloride gas in water is called concentrated hydrochloric acid. If 46.5g of hydrogen chloride gas is required to prepare 100mL of concentrated hydrochloric acid at 25C, what is the solubility of hydrogen chloride at 25C?

mol/L = HCl

Factors that Affect Solubility

• Temperature• temperature

(energy) increases the solubility

• temp decreases the solubility of gases

• Pressure• Increasing the

pressure of gases increases the solubility • no effect on

liquids or solids

• Nature of Solute and Solvent• Depends on the nature of the

bonds (polar and non polar)• i.e. grease will dissolve in gas

but not in water

Precipitates• 2 aqueous solutions combine &

the positive ion (cation) of one combines with the negative ion (anion) of the other to form an insoluble compound (a solid precipitate)

•Write the net ionic equation and use a solubility table to determine whether a solid will form

Example

• Write the net ionic equation for the formation of a precipitate when aqueous solution of potassium hydroxide and magnesium chloride are mixed

• 2KOH(aq) + MgCl2(aq) 2KCl(?) + Mg(OH)2(?)

• Total ionic equation

• Net ionic equation