1. Solutions, Acids & Bases

2. Solutions Uniform mixture that contains a solvent and at least one solute Solvent=dissolves the other substances, concentration is greater Solute=dissolved in the solvent, concentration is smaller Water dissolves so many substances that it is called the “universal solvent”

3. Colloids Mixture that contains small, undissolved particles that do not settle out Contains larger particles than a solution Particles are still too small to be seen easily but are large enough to scatter a light beam Example: milk—contains fats and proteins that form globular particles, scatters light so that you cannot see through a glass of milk

4. Suspensions Mixture in which particles can be seen easily separated by settling or filtration Does not have the same properties throughout Contains visible particles that are larger than the particles in solutions or colloids Example: Pepper in water

5. Particles in Solution Ionic compound (such as NaCl)— positive and negative ions are attracted to the polar water molecules and NaCl breaks apart Molecular compound (such as sugar)—breaks up into individual neutral molecules. Polar water molecules attract the slightly polar sugar molecules, causes the sugar molecules to move away from each other

6. Solubility Measure of how much solute can dissolve in a solvent at a given temperature Unsaturated solution—can continue to dissolve more solute Saturated solution—added so much solute that no more dissolves.

7. Acids Tastes sour Reacts with metals and carbonates Turns blue on litmus paper red Common acids: Hydrochloric acid Nitric acid Sulfuric acid Carbonic acid Acetic acid

8. Bases Tastes bitter Feels slippery Turns red litmus paper blue

9. Uses of Acids & Bases

10. Important Acids & Bases AcidsFormulaBasesFormula Hydrochloric AcidHClSodium Hydroxide NaOH Nitric AcidHNO 3 Potassium hydroxide KOH Sulfuric AcidH 2 SO 4 Calcium Hydroxide Ca(OH) 2 Carbonic AcidHC 2 H 3 O 2 Aluminum Hydroxide Al(OH) 3 Acetic AcidHC 2 H 3 O 2 AmmoniaNH 3

11. Acids in Solution Produce one or more hydrogen ions and a negative ion in solution with water Hydrogen ion (H + ) is an atom of hydrogen that has lost its electron The negative ion may be a nonmetal or a polyatomic ion The hydrogen ion is the key to an acidic reaction HCl + H 2 0>>>> H + + Cl - The production of the hydrogen ion gives an acid its properties

12. Bases in Solution Most contain positive ion combined with hydroxide ion (OH - ) In water, the two are separated NaOH + H 2 0>>>> Na + + OH - Not all bases have an OH to give off, such as ammonia (NH 3 ). They react with the water to create OH - NH 3 + H 2 0>>>>NH 4 + + OH - The production of OH - give bases their properties

13. pH Scale Method to measure strength of acids and bases Scale of 0-14 to express concentration of H + ions A low pH indicates that the concentration of hydrogen ions is big A high pH indicates that the concentration of hydrogen ions is low Below 7=acidic Above 7=basic 7=neutral

14. pH Scale