Acids and Bases And others Acids For thousands
Acids and Bases And others…
Acids ¥ 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"
Acid Characteristics ¥ 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
Examples of Acids ¥ ¥ ¥ ¥ ¥ 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 ¥ 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
Base Characteristics ¥ Bases have a p. H 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
Base Examples ¥ ¥ Mustards Many medicines ¥ Ie. Magnesium oxide – treats indigestion ¥ Bleaches, soaps, toothpastes, window cleaners and other cleaning agents Sodium Hydrogen Carbonate (bread soda). Sodium hydroxide (Na. OH) 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
p. H Scale ¥ Measure of how acidic or how basic Stomach Acid HCl Vinegar Rain Lemon Juice Soda More Acidic Pure water Egg Whites Baking Soda Mineral Lime Ammonia Tums Na. OH Drano More Basic
¥ ¥ ¥ ¥ ¥ ACIDS 1 - HCL 2 – Stomach Acid 3 – Lemon Juice 4 - Vinegar 5 - Soda 6 – Rain Water Neutral: 7 – Pure Water ¥ ¥ ¥ ¥ BASES 8 – Egg Whites 9 – Baking Soda 10 - Tums 11 - Ammonia 12 – Mineral Lime 13 - Drano 14 - Na. OH
Acids and Bases… and others IDENTIFICATION
Identifying Acids ¥ Acids start with “H” ¥ Examples: HCl ¥ H 2 SO 4 ¥
Identifying Bases ¥ Bases end in “OH” (hydroxides) ¥ Examples: Na. OH ¥ Ca(OH)2 ¥
Identifying Metals ¥ 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? ¥
Identifying Carbonates ¥ Carbonates “CO 3” ¥ Examples Na 2 CO 3 ¥ Mg. CO 3 ¥ end with the elements
Identifying Salts ¥ Salts are two elements bonded together from opposite sides of the periodic table or with a polyatomic ion ¥ What is polyatomic ions? ¥ Examples Na. Cl ¥ Al. F 3 ¥ KNO 3 ¥
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