1. SOLUTIONS

2. Objective SWBAT identify types of solutions. SWBAT identify electrolytic solutions.

3. Warm-Up What Do You Know About Solutions?

4. Properties of Solutions Particles are very small Particles are evenly distributed The particles of a solution will not separate (it doesn’t matter how long you let it stand)

5. Solutions Solute - the substance that is dissolved Solvent - the substance that does the dissolving A substance that dissolves in another substance is soluble in that substance. A substance that does not dissolve in another substance is insoluble.

6. Types of Solutions solute solventexample Gasgasair Gasliquidseltzer water (CO 2 in water) Liquidliquidantifreeze (ethylene glycol in water) Solidliquidocean water (salt in water) Gassolidcharcoal filter (poisonous gases in carbon) Liquidsoliddental filling (mercury in silver) Solidsolidsterling silver (copper in silver)

7. Types of Solutions Solid solution- Alloys are the most common solid solutions containing 2 or more metals Liquid solution- Miscible - 2 or more liquids that can mix in any amount Immiscible - liquids that cannot mix in any proportions Aqueous solutions have water as the solvent

8. Electrolytes Soluble ionic compounds dissolve in water to form ions (charged particles). These ions move within the solution. An electric current can pass through the solution. A substance that dissolves in water to form a solution that conducts an electric current is called an electrolyte.

9. A solution containing neutral solute molecules will not conduct electricity because there are non ions moving freely in solution. A substance that dissolves in water to form a solution that does not conduct an electric current is called a nonelectrolyte. The concentration of a solution is the amount of solute in a given amount of solvent of solution.

10. Molarity “M” Use molarity to express the concentration of a solution. Molarity= moles of solute liters of solution Note: use a capital “M” for the units of molarity

11. Calculating Molarity Step 1: Determine which is the solute and which is the solvent Step 2: convert the solute from grams to moles Step 3: convert solvent to liters (if necessary) Step 4: Divide the moles of solute by the liters of solvent

12. Molality “ m ” Molality can also be used to express the concentration of a solution. Molality = moles of solute kilograms of solvent Note: use a lowercase “m” for the units of molality

13. Calculating Molality Step 1: determine the solute and solvent Step 2: Convert the solute from grams to moles Step 3: convert solvent to kilograms (kg) Step 4: Divide the moles of solute by the kilograms of solvent

14. Mole Fraction Mole fraction = moles of component total moles of solution Use “X” to denote the mole fraction and use a subscript to show which component of the solution is being solved for.

15. Mole Fraction X solute = moles of solute total moles of solution X solvent = moles of solvent total moles of solution (note: mole fraction calculations do not have any units)

16. Mole Fraction If you add the mole fractions for the solute and the solvent they must equal 1. X solute +X solvent =mol solute + mol solvent = 1 mol solution mol solution

17. Saturation A solution is saturated if it contains as much solute as can possible be dissolved under the existing conditions of temperature and pressure. A solution that has less than the maximum amount of solute that can be dissolved is called an unsaturated solution.

18. Solutions A solution that contains a greater amount of solute than that needed to form a saturated solution is called a supersaturated solution. (These are very unstable solutions. Solute particles will begin to reform.)