1. SOLUTIONS AND MOLARITY STANDARDS 6A, 6C, 6D

2. MIXTURES MIXTURE – HAS VARYING COMPOSITION AND IS MADE UP OF A NUMBER OF PURE SUBSTANCES HOMOGENEOUS – UNIFORM IN COMPOSITION THROUGHOUT A GIVEN SAMPLE; EXAMPLE – SALT WATER HETEROGENEOUS – HAVE SEPARATE, DISTINCT REGIONS WITHIN THE SAMPLE; COMPOSITION AND PROPERTIES VARY FROM ONE PART OF THE MIXTURE TO ANOTHER; EXAMPLE – CHOCOLATE CHIP COOKIE

3. I. WHAT IS A SOLUTION? A.A SOLUTION IS A HOMOGENEOUS MIXTURE OF TWO OR MORE SUBSTANCES IN ONE PHASE. B.EXAMPLES: BRASS (S IN S) AIR (G IN G) CREAM (L IN L)

4. C. TWO PARTS TO A SOLUTION: 1.SOLUTE: SUBSTANCE THAT GETS DISSOLVED. 2.SOLVENT: SUBSTANCE THAT DOES THE DISSOLVING EX. SALT WATER SOLUTION SOLUTE: SALT SOLVENT: WATER *WATER IS KNOWN AS THE UNIVERSAL SOLVENT

5. D. THREE CLASSIFICATIONS OF SOLUTIONS 1.SATURATED: CONTAINS MAXIMUM AMOUNT OF SOLUTE A SOLVENT CAN DISSOLVE (SMALL AMTS OF SOLUTE ARE UNDISSOLVED ON BOTTOM) *All classifications are based on how much solute has been added to a solvent! 2.Unsaturated: Contains less than max. amount of solute a solvent can dissolve. (leaves no amt. of solute undissolved)

6. 3. Supersaturated: Contains more than max. amount of solute a solvent can dissolve. (leaves a lot of solute undissolved and re- crystallized – hardened) Heating can help make a super saturated soln, when heat is removed, soln will re-crystallize.

7. E. SOLUBLE, INSOLUBLE, IMMISCIBLE, AND MISCIBLE A SUBSTANCE THAT DISSOLVES IN A SOLVENT IS SAID TO BE SOLUBLE IN THAT SOLVENT (E.G. SUGAR IN WATER). A SUBSTANCE THAT DOES NOT DISSOLVE IN A SOLVENT IS SAID TO BE INSOLUBLE IN THAT SOLVENT (E.G. SAND IN WATER). LIQUIDS THAT DO NOT MIX WITH ONE ANOTHER ARE IMMISCIBLE. LIQUIDS THAT MIX WITH ONE ANOTHER ARE MISCIBLE.

8. DEMONSTRATIONS WATER AND VINEGAR WATER AND OIL 1.WHICH IS A SOLUTION? 2.WHICH IS MISCIBLE? 3.WHICH IS IMMISCIBLE?

9. F. SOLVATION WHEN AN IONIC SOLUTE SUCH AS NACL IS PLACED IN WATER, THE POLAR SOLVENT MOLECULES ATTRACT THE SOLUTE IONS. AS INDIVIDUAL SOLUTE IONS BREAK AWAY FROM THE CRYSTAL, THE (-) AND (+) CHARGED IONS BECOME SURROUNDED BY SOLVENT MOLECULES AND THE IONIC CRYSTALS DISSOLVE. THIS IS SOLVATION IONIC CPDS THAT HAVE ION ATTRACTIONS STRONGER THAN THE ATTRACTIONS EXERTED BY THE SOLVENT CANNOT BE SOLVATED. INSOLUBLE WHEN DOES SOLVATION HAPPEN? WHEN THE SOLVENT AND SOLUTE ARE ALIKE. “LIKE DISSOLVES LIKE” EX: POLAR SOLVENTS (WATER) DISSOLVE IONIC CPDS AND POLAR CPDS NONPOLAR SOLVENTS DISSOLVE NONPOLAR CPDS

10. II. HOW IS CONCENTRATION MEASURED? A.CONCENTRATION OF SOLUTIONS IS MEASURED IN MOLARITY. B.MOLARITY (M): MOLES OF SOLUTE DIVIDED BY LITERS OF SOLUTION. EQUATION: *The larger the number for Molarity, the more concentrated the solution! (Ex. 6M vs. 0.5M)

11. MOLARITY EXAMPLES: 1.IF 4 MOLES OF HCL ARE DISSOLVED IN 8 LITERS OF SOLUTION, WHAT IS THE CONCENTRATION? 2. IF 80 GRAMS OF NAOH IS DISSOLVED TO MAKE 1 LITER OF SOLN, WHAT IS THE MOLARITY? 3. IF THE MOLARITY OF A 2 LITER SOLN OF KNO 3 IS 6 M, HOW MANY MOLES WERE DISSOLVED?

12. III. DILUTIONS A.DILUTION: REDUCING THE CONCENTRATION OR MOLARITY OF A SOLUTION BY ADDING WATER. EQUATION:

13. C. DILUTION EXAMPLES: IF 2 L OF WATER IS ADDED TO 1 L OF A 12 M SOLUTION OF HCL, WHAT IS THE NEW CONCENTRATION? HOW WOULD YOU PREPARE 500ML OF 1M SOLUTION FROM A 12M STOCK SOLUTION OF NAOH?