1 Terms Soluble Insoluble Saturated solution Unsaturated solution Supersaturated solution Concentration Molarity Dilution

2 Chapter 15 SOLUTIONS

3 Some solutions contain ELECTROLYTES HCl, MgCl 2, and NaCl are strong electrolytes. - dissociate completely into ions. weak electrolytes. - dissociate a little into ions. Aqueous Solutions

4 Some compounds dissolve in water but do not conduct electricity. They are called: nonelectrolytes. Examples include: sugarethanol ethylene glycol Examples include: sugarethanol ethylene glycol

5 Colligative Properties depend on the concentration of particles in a solution, not of the identity of the particles.  Boiling Point Elevation  Freezing Point Depression  Osmotic Pressure

6 Freezing Point Depression Each mole of solute particles lowers the freezing point of 1 kilogram of water by 1.86 degrees Celsius. Each mole of nonvolatile solute particles raises the boiling point of 1 kilogram of water by 0.51 degrees Celsius. Boiling Point Elevation

7 Electrolyte or Nonelectrolyte! Test each sample to see if it is a strong electrolyte, weak electrolyte, or nonelectrolyte.

8 Parts of a Solution SOLUTE –part that is being dissolved SOLVENT – part that dissolves the solute Solute + Solvent = Solution

9 How Salts dissolve H H O H H O H H O H H O H H O H H O H H O H H O H H O

10 Dissolving and Solutions

11 Solubility curve Saturated Unsaturated Supersaturated

12 Solubility curve Any point on a line represents a saturated solution. In a saturated solution, the solvent contains the maximum amount of solute. Example 

13 Solubility curve Any point below a line represents an unsaturated solution. In an unsaturated solution, the solvent contains less than the maximum amount of solute. Example 

14 Solubility curve Any point above a line represents a supersaturated solution. In a supersaturated solution, the solvent contains more than the max solute. It is unstable TemporaryTemporary accomplished in one of two ways:accomplished in one of two ways: 1.Warm the solution 2.Evaporate some of the solvent Example 

15 Solubility curve Any solution can be made saturated, unsaturated, or supersaturated by changing the temperature.

16 Solubility Curve Determine if each of the following is unsaturated, saturated, or supersaturated. 55g of NH 3 at 20 o C._________ 80g of NaNO 3 at 10 o C. _________ 10g of Ce 2 (SO 4 ) 3 at 10 o C_________ 145g of NaNO 3 at 80 o C. _________ 25g of KNO 3 at 60 o C. _________ 35g of NaCl at 100 o C. _________ 65g of NH 4 Cl at 80 o C. _____________ 12g of NH 3 at 90 o C. ______________

17 The concentration of a solution tells you how much solute that is dissolved in a given amount of solvent (water). The molarity is the concentration of a solution. Molarity=Moles Liter moles of NaCl is dissolved in 4.0 L of water, calculate the molarity. Molarity= =0.56 moles/liter =0.56 M (Molar) where M means moles per 1 liter

g KOH is dissolved in 250. mL of water, calculate the molarity. Molarity= =0.356 M

19 Step 1: Change mL to L. = L Step 2: Calculate Moles = moles Step 3: Convert moles to grams. = 1.13 g = 1.13 g USING MOLARITY moles = MV What mass of oxalic acid, H 2 C 2 O 4, is required to make 250. mL of a M solution?

20 Molarity Practice What is the molarity of an aqueous solution containing 40.0 g of glucose (C 6 H 12 O 6 ) in 1.5 mL of solution? What is the molarity of bleach solution containing 9.5 g of NaOCl per liter of bleach?

21 3.How many moles are there in 205. mL of a M solution? moles

22 4. How many grams NaCl are there in mL of M solution? 7.31 g

23 Dilutions

24 Diluting Solutions Concentrated solutions have a relatively high molarity. Dilute solutions have a relatively low molarity. M 1 V 1 = M 2 V 2 M 1 = the initial molarityM 2 = the final molarity V 1 = the initial volumeV 2 = the final volume

25 NaCl (aq) Concentrated solution Diluted solution water

mL of 0.10 M solution is diluted by adding 75.0 mL of water. Calculate the molarity of the new solution. M 1 V 1 = M 2 V 2 Initial Solution M 1 = 0.10 M M 2 = ? V 1 =25.0 mL V 2 = mL 25.0 mL mL (0.10 M)(25.0 mL) = M 2 (100.0 mL) M 2 = M

27 2.What volume of M CoCl 2 solution can be diluted to mL in order to make a M solution? Initial Solution M 1 V 1 = M 2 V 2 M 1 = M M 2 = M V 1 = ? V 2 = mL (0.250 M) V 1 = ( M)(100.0 mL) V 1 = 6.00 mL

mL of M CuSO 4 solution is diluted to mL. Calculate the new concentration and the number of grams CuSO 4 in the new solution. Initial Solution M 1 V 1 = M 2 V 2 M 1 = M M 2 = ? V 1 = 50.0 mL V 2 = mL (0.500 M)(50.0 mL) = M 2 (250.0 mL) M 2 = M L0.500 mol 1 L xx g 1 mol = 3.99 g

29 Practice 1) If I add 25 mL of water to 125 mL of a 0.15 M NaOH solution, what will the molarity of the diluted solution be? 2) If I add water to 100 mL of a 0.15 M NaOH solution until the final volume is 150 mL, what will the molarity of the diluted solution be? 3) How much 0.05 M HCl solution can be made by diluting 250 mL of 10 M HCl?

30 Practice 4) I have 345 mL of a 1.5 M NaCl solution. If I boil the water until the volume of the solution is 250 mL, what will the molarity of the solution be? 5) How much water would I need to add to 500 mL of a 2.4 M KCl solution to make a 1.0 M solution?

31 Practice grams of lithium sulfate are dissolved to make mL of solution x grams of Pb(C 2 H 3 O 2 ) 4 are dissolved to make 3.50 mL of solution grams of sodium hydroxide to 750 mL of water.