SOLUTIONS

RECALL TYPES OF MIXTURES: SUSPENSIONS COLLOIDS SOLUTIONS All mixtures are physically combined and can be physically separated.

DEFINITION A solution is a homogeneous mixture of two or more substance in a single physical state

Parts of a solution SOLUTE – the substance that is dissolved SOLVENT- the substance that does the dissolving

Definitions Solute Solute - KMnO 4 Solvent Solvent - H 2 O

TYPES OF SOLUTIONS SOLUTESOLVENTEXAMPLE GAS Air GASLIQUIDSeltzer (CO 2 ) LIQUID Antifreeze (ethyl glycol in water) SOLIDLIQUIDSea water ( salt in water) GASSOLIDCharcoal filter (poisonous gases in carbon) LIQUIDSOLIDDental filling (mercury in silver) SOLID Sterling silver (copper in silver)

SOLID SOLUTION Contain two or more metals called alloys Formed by melting the components and mixing them together and allowing them to cool Properties of alloys are different from the original component metals

TYPES OF ALLOYS ALLOYCOMPONENTUSES BabbittTin, antimony, copperBearings Bell metalCopper, tinBells Coinage metalsCopper, tin, zincCoins 16 karat goldGold, copper, silverJewelry SterlingSilver, copperJewelry, flatware NichromeNickel, iron, chromium, manganese Heating elements

GASEOUS SOLUTIONS All mixture of gases Properties depend on the properties of its components Example: Nitrogen in air serves as a gas that dilutes pure oxygen which is toxic to people and animals, and is very combustible.

LIQUID SOLUTIONS Most familiar type of solution The solvent and the solution are liquids Solute may be a gas, a solid, or a liquid It is proper to describe liquids that are soluble to each other as MISCIBLE or can mix. And insoluble liquids as IMMISCIBLE. Or cannot mix. Example: alcohol is miscible in water while oil is immiscible in water.

Important terminologies: Soluble – substance that dissolves another substance Insoluble – substance that does not dissolve another substance Miscible – liquids that are completely soluble in each other or can mix Immiscible – liquids that are not soluble in each other or cannot mix

AQUEOUS SOLUTIONS Solutions with water as the solvent Aqueus, means like or containing water. Substances that dissolve in water are classified according to whether they produce ions or molecules in solution. Solutions that conduct electricity are called ELECTROLYTES.

SOLUBILITY

Solubility Solubility maximum grams of solute that will dissolve in 100 g of solvent at a given temperature g solute/100 mL H 2 O varies with temp based on a saturated solution

Solubility SATURATED SOLUTION no more solute dissolves UNSATURATED SOLUTION more solute dissolves SUPERSATURATED SOLUTION becomes unstable, crystals form increasing concentration

Determine if a solution is saturated, unsaturated,or supersaturated. If the solubility for a given substance places it anywhere on it's solubility curve it is saturated. If it lies above the solubility curve, then it's supersaturated, If it lies below the solubility curve it's an unsaturated solution.

Temp. ( o C) Solubility (g/100 g H 2 O) KNO 3 (s) KCl (s) HCl (g) SOLUBILITY CURVE Solubility  how much solute dissolves in a given amt. of solvent at a given temp. below unsaturated:solution could hold more solute; below line on saturated:solution has “just right” amt. of solute; on line supersaturated:solution has “too much” solute dissolved in it; above the line

ToTo Sol. ToTo Solids dissolved in liquids Gases dissolved in liquids As T o, solubility

Sometimes you'll need to determine how much additional solute needs to be added to a unsaturated solution in order to make it saturated. For example,30 grams of potassium nitrate has been added to 100 cm 3 of water at a temperature of 50ºC.

How many additional grams of solute must be added in order to make it saturated? From the graph you can see that the solubility for potassium nitrate at 50ºC is 84 grams

If there are already 30 grams of solute in the solution, all you need to get to 84 grams is 54 more grams ( 84g-30g )

Solubility Table LeMay Jr, Beall, Robblee, Brower, Chemistry Connections to Our Changing World, 1996, page 517 shows the dependence of solubility on temperature Solubility vs. Temperature for Solids Solubility (grams of solute/100 g H 2 O) KI KCl NaNO 3 KNO 3 HClNH 4 Cl NH 3 NaCl KClO 3 SO 2 gases solids

Classify as unsaturated, saturated, or supersaturated. per 100 g H 2 O 80 g NaNO 30 o C 45 g 60 o C 50 g NH 10 o C 70 g NH 4 70 o C =unsaturated =saturated =unsaturated =supersaturate d Solubility vs. Temperature for Solids Solubility (grams of solute/100 g H 2 O) KI KCl NaNO 3 KNO 3 HClNH 4 Cl NH 3 NaCl KClO 3 SO 2 gases solids