SOLUTIONS

What is a solution?  A mixture that has the same composition throughout  Also known as a homogenous mixture  Made of solutes and solvent

Parts of a Solution  The substance that is doing the dissolving  The substance being dissolved SolventSolute

 Solid dissolving in a liquid  Solid – solute  Liquid – solvent  Liquid dissolving in a liquid  Liquid in a larger amount - solvent

Water – Universal Solvent  Water has a positive end and a negative end.  The positive end is attracted to our negative end.  Water molecules pull apart the solute and then they mix evenly, forming a solution.  Just remember –  LIKE DISSOLVES LIKE!

Dissolving Solutes  To speed up a solution:  Stirring Brings more fresh solvent in direct contact with the solute  Smaller crystal size Increases the surface area which allows more solvent to come in contact with the solute  Increasing temperature The speed of the solvent increases and causes them to bump into the solute Solute particles come loose and dissolve faster

Solubility  The maximum amount of solute that can be dissolved in a given amount of solvent at a given temperature  Measured in grams per 100 g of water  Depends on the nature of the substances

Concentration large amount of solute is dissolved in the solvent Concentrated small amount of solute is dissolved in the solvent Dilute

Concentration

Types of Solutions A solution that can dissolve more solute at a given temperature Unsaturated A solution that contains all the solute it can hold at a given temperature More solute can be added if heat is applied to the solution Saturated A solution that contains more solute that a saturated solution at the same temperature Solute tends to collect at the bottom Supersaturated

Solubility Curves  Each line represents a particular substance.  Shows type of solution  Above the line – supersaturated  On the line – saturated  Below the line - unsaturated  Graph  Independent variable – Temperature in Celsius  Dependent variable – grams per 100 g of water

Solubility Curves

Effects of Solute Particles  Adding a solute to a solvent lowers the freezing point of the solvent.  Example – antifreeze  Increasing the boiling point depends on the number of solute particles in the solvent

Questions