Families of Chemical Compounds Chapter 9
Groups of Compounds Compounds are grouped based on physical and chemical properties Types: Organic, Acids, Bases, and Salts
Acids and Bases Examples of Acids Aspirin Vitamin C Eye drops Oranges Grapefruits Lemons Grapes Apples Milk Tea Pickles Vinegar Carbonated beverages (soda, etc.)
Acids and Bases Examples of Bases Lye Milk of Magnesia Deodorants Ammonia Soaps
Some Uses of Each Acids Stomach acid helps digest food Acids are used to clean metals Bases Milk of Magnesia helps neutralize acid in stomach Deodorant counters acidic body sweat
Properties of Acids All acids have certain physical and chemical properties when dissolved in water. Sour taste (never taste a solution to determine whether it is acidic or not!)
Properties of Acid An acid will affect an indicator a certain way Indicators are compounds that have a definite change when mixed with and acid or base. color
Properties of Acids Examples of indicators: Litmus paper (blue turns red in acid, red stays red) Phenolphthalein (colorless in acid solution)
Properties of Acids Acids react with active metals to form hydrogen gas and a metal compound. (This process wears away, or corrodes, the metal and produces a residue). Example: sulfuric acid in a car battery can corrode the terminals and leaves a residue.
Properties of Acids Acids contain Hydrogen When dissolved in water, acids ionize to produce positive hydrogen ions ( H+ ) Acids are proton donors in water
Common Acids Strong Acids Sulfuric Acid (H2SO4) Nitric Acid (HNO3) Hydrochloric Acid (HCl) These ionize heavily in water These acids are good electrolytes
Common Acids Weak Acids Acetic Acid (HC2H3O2) Carbonic Acid (H2CO3) Boric Acid (H3BO3) These ionize weakly in water These acids are poor electrolytes An electrolyte is a substance whose water solution conducts an electrical current.
Properties of Bases All bases share certain physical and chemical properties Bitter taste (never taste a solution to determine whether it is basic or not! Can be poisonous & corrosive.) Slippery to the touch
Properties of Bases A base will affect an indicator a certain way -Litmus paper (red turns blue, blue stays blue) -Phenolphthalein (turns bright pink)
Properties of Bases Dissolves fats and oils (acts with fat or oil to form a soap) Ammonium hydroxide is used as a cleaner because it cuts grease Sodium hydroxide (lye) cleans clogged drains (strong base)
Properties of Bases All bases contain the hydroxide ion ( OH- ) When dissolved in water, bases produce the hydroxide ion Bases are proton acceptors
Common Bases Strong Bases Potassium Hydroxide (KOH) Sodium Hydroxide (NaOH) Calcium Hydroxide (Ca(OH)2) These ionize heavily in water These bases are good electrolytes
Common Bases Weak Bases Ammonium hydroxide (NH4OH) Aluminum hydroxide (Al(OH)3) These ionize weakly in water These bases are poor electrolytes
Acids and Bases in Solution: Salts Solutions can be: Acidic Basic Neutral
The ph Scale The ph scale is used to measure the acidity of a solution (how acidic it is) The ph of a solution is a measure of the hydronium ion (H3O+) concentration A hydronium ion is made when an acidic solution gives a hydrogen ion (H+). That ion bonds to a water molecule (H2O)
The ph Scale Most Acidic Water 0 14 7 Basic Most
The ph Scale ph examples: Lemons 2 Vinegar 2 Apples.3 Bananas..5 Shampoo 5 Water..7 Eggs.8 Ocean water...8 Soap..10 Milk of Mag 10 Ammonia 11 Lye..14
Determining Solution ph Types of indicators: Litmus paper All Show a Phenolphthalein specific ph paper color change Methyl Orange per ph level Bromthymol Blue Red-cabbage juice Grape juice (pink = acidic, yellow = basic) Tea (add lemon juice and see what happens) ph Meter (most accurate)
Formation of Salts When acids react chemically with bases, they form another class of compounds: SALTS A salt compound is formed from what is left over after the H+ and the OH- make water
Formation of Salts A salt is a neutral substance Acid + Base Salt + Water This process is called Neutralization Acid Base water Ex. HCl + NaOH H2O + NaCl
Formation of Salts Many of these salts are insoluble in water they do not dissolve in water (remains in solid phase).
Formation of Salts A neutralization reaction is a Doublereplacement reaction Ex. A dangerous acid and a dangerous base can be mixed together to form a harmless salt and water (neutral).
~The End~