What we’ve done…. Monday: notes 15.2/16.1 P457 #8-15 p477 #3-6 Tuesday: notes 15.3/16.2 P462 #16-21 p486 #16-23 Wednesday: lab separating mixtures Hmwk: p499 #50-53

Acids & Bases

Acids 1. Taste sour Acids taste sour: examples are citric acid in citrus fruits, acetic acid in vinegar…sour pickles

2. Donates Hydrogen ions H+ 3. Forms Hydronium ions H3O+ Products of a chemical reaction will show H3O Hydrogen proton leaves acid molecule and attaches to a water changing it from H2O to H3O

Products of a chemical reaction will show H3O HCl + H2O  H3O+ + Cl- Hydrogen proton leaves acid molecule and attaches to a water changing it from H2O to H3O

4. Turns Universal Indicator to RED Blue litmus paper chemically reacts with acid and turns red Litmus paper made from lichens

5. It Burns skin and tissue Acid will burn skin and other tissues (eyeballs, etc.) be careful when using strong acid solutions in labs

6. Conducts electricity Only when dissolved in water Acid disassociates the H+ from the other (such as H+ and Cl- when HCl dissolved in water) Results in movement of ions (electrons) Weak acids = conduct less Strong acids = conduct more Sulfuric acids in car batteries

7. Crystalline Solid When undissolved, exists as a crystalline solid

Stomach acid Battery acid Examples Citric acid (vitamin c in fruit) Acetic acid (vinegar) Gastric juices (stomach acid) Sulfuric acid (battery)

Bases 1. Tastes Bitter Unsweetened chocolate Walnuts Almonds Coffee Escarole Squeaky/dry feel in mouth

KOH  K+ + OH- NH3 + H2O  NH4+ + OH- 2. Hydroxide ions OH- KOH  K+ + OH- NH3 + H2O  NH4+ + OH- 2 ways of creating OH- ions in solution: 1. Either by disassociating OH- from the compound in a decomposition reaction or 2. Stealing an H+ from water in a double displacement reaction

3. Turns Universal Indicator to BLUE

4. Corrosive (feels slippery) Dissolves lipids in your skin and feels slippery

5. Can also conduct electricity

Examples Sodium hydroxide pellets Ammonia = fertilizers, cleaners Sodium hydroxide (lye) = baking soda, soaps, paper Calcium hydroxide (lime) = cement Potassium hydroxide (potash) = bleaching

Soap = basic surrounds oily substances allows emulsion in water Whisked away!

pH Scale measures hydronium ions (H3O+) The pH scale is only used to measure concentrations of hydronium ions Large amounts in acids Small amounts in bases

Comparative concentrations Hydronium ions (acid) Hydroxide ions (base) 0 - 6 Acids A lot A little 7 neutral = 8 -14 Bases

Concentration changes by powers of 10 pH =1 has 10x more acidic (H+) than pH = 2 pH = 1 has 100x more acidic (H+) than pH = 3 More  Less 1 2 3 4 5 6 7 8 9 10 11 12 13 14 10 100 1000 10000 100000

Acid + Base  water H3O+ + OH-  H2O Neutralization Acid + Base  water H3O+ + OH-  H2O

KOH + HNO3  H2O + K+ + NO3- Is it balanced?

Must have = amounts of hydronium and hydroxide ions to completely neutralize

The End Homework--- Due Monday! (from Wednesday) p499 #50-53 (new) p499 #54-55 (new) p501 #78, 81, 82 Don’t forget to turn in Lab: Separating Mixtures today!!!