1. Solutions and pH Chapter 2 sec. 2.2 pg 41- 43

2. Solutions Mixtures – a combination of substances that retain their original properties Ex. trail mix, air, salt water

3. Solutions Solution – mixture of one or more substances uniformly distributed in another substance. Can be solid, liquid, gas ex. Plasma (liquid) brass (solid)  copper and zinc soda (liquid/gas)  water and CO2

4. 2 parts: 1. Solute – substance being dissolved 2. Solvent - substance doing dissolving Salt water: salt = solute water = solvent Aqueous solutions- water is the solvent due to hydrogen bonding Water = universal solvent because it can dissolve most things

5. Concentration Concentration - amount of solute dissolved in a fixed amount of solution When no more solute can be dissolved….solution is SATURATED Salt will no longer dissolve 

6. Acids & Bases The Homeostasis of living things depends on the degree of acidity (acid) and alkalinity (base) in certain areas

7. Water  Acids and bases are solutions made by the dissociation of water  Water naturally breaks down into ions of opposite charges, this is called dissociation.  Water will form these ions naturally (H3O+ & OH - ) and in EQUAL amounts. H 2 O  H + + OH - This is why water is NEUTRAL! Hydronium (H3O+) ions = hydroxide (OH - ) ions

8. Acids & Bases Acidity= measure of the amount of Hydronium (H 3 O+) ions dissolved in a solution. Alkalinity (a/k/a basic solution)= measure of the amount of hydroxide (OH - ) ions dissolves in a solution

9. Acids - more H + ions released -pH < 7 -Sour taste -Corrosive on metals -Burns skin Ex. Orange juice, vinegar, sulfuric acid *Homeostasis relevance- your stomach must have a certain acidity to function properly

10. Bases - more OH - ions released -pH > 7 -Tastes bitter -Slippery -Irritate the skin -Ex. NaOH Homeostasis relevance- your small intestine needs a certain alkalinity (basic) to function properly

11. pH Scale -Used to measure the amounts of H 3 O+ and OH - ions in a solution -Tells you how acidic or basic something is -Ranges 0-14, 7 = neutral above 7 = base below 7 = acid -Ten fold system -Measure pH with litmus paper

13. Buffers Buffers- chemical substances that neutralize small amounts of acids and bases Ex. Acids { stomach acid & urine Ex. Bases { blood & intestinal fluid -If not at the proper pH level, these body systems will not function properly and… you’ll need to use a Buffer ex. Alka seltzer