And others…

 For thousands of years people have known that vinegar, lemon juice and many other foods taste sour.  However, it was not until a few hundred years ago that it was discovered why these things taste sour – They taste sour because they are all acids.  The term acid, in fact, comes from the Latin term acere, which means "sour"

 Acids have a PH of less than 7.  Acids taste sour  Acids are corrosive to metals  Acids can ‘burn' your skin  Acids change litmus paper red  Litmus paper helps to determine acids and bases  Acids become less acidic when mixed with bases.

 orange juice, lime juice or lemon juice (citric acid)  vinegar (acetic acid)  aspirin (salicylic acid)  yogurt (lactic acid)  Coca-Cola (phosphoric acid)  toilet bowl cleaner (sulfuric acid)  bathroom cleaner (muriatic acid)  wine (tartaric acid and/or malic acid)  vitamin C tablets (ascorbic acid)  urine (uric acid)

 Bases can also be called alkalis.  Bases can be thought of as the chemical opposite of acids.  A reaction between an acid and base is called neutralization  We will talk more about this tomorrow An example of base: soap

 Bases have a pH more than 7  Bases feel slippery  Converts fats and oils in skin to glycerin (slick feel)  In a sense, bases dissolve your skin… think of getting Clorox bleach on your skin  Bases turns litmus paper to a blue color.  Bases become less basic when mixed with acids.  Bases reacts with acids to form salt and water

 Mustards  Many medicines  Ie. Magnesium oxide – treats indigestion  Bleaches, soaps, toothpastes, window cleaners and other cleaning agents  Sodium Hydrogen Carbonate (bread soda).  Sodium hydroxide (NaOH) or caustic soda  Calcium hydroxide ( Ca(OH) 2 ) or limewater  Ammonium hydroxide (NH 4 OH) or ammonia water  Magnesium hydroxide ( Mg(OH) 2 ) or milk of magnesia

 Measure of how acidic or how basic More AcidicMore Basic HCl Stomach Acid Lemon Juice Vinegar Soda Rain NaOH Pure water Egg Whites Baking Soda Drano Mineral Lime Ammonia Tums

 ACIDS  1 - HCL  2 – Stomach Acid  3 – Lemon Juice  4 - Vinegar  5 - Soda  6 – Rain Water  BASES  8 – Egg Whites  9 – Baking Soda  10 - Tums  11 - Ammonia  12 – Mineral Lime  13 - Drano  14 - NaOH  Neutral:  7 – Pure Water

Acids and Bases… and others

 Acids start with “H”  Examples:  HCl  H 2 SO 4

 Bases end in “OH” (hydroxides)  Examples:  NaOH  Ca(OH) 2

 Metals are single elements found on the left side of the periodic table  Separated from non-metals by metalloids (staircase)  Examples  Al  Li  Can you name any other ones?

 Carbonates end with the elements “CO 3 ”  Examples  Na 2 CO 3  MgCO 3

 Salts are two elements bonded together from opposite sides of the periodic table or with a polyatomic ion  What is polyatomic ions?  Examples  NaCl  AlF 3  KNO 3