Properties of Acids and Bases
A. Acids
Examples:
Sour milk – lactic acid
Vinegar – acetic acid
Carbonated beverages – phosphoric acid
Citrus fruits – citric acid
Apples – malic acid
Grapes – tartaric acid
Properties:
1. Have a sour taste
2. Will change the color of acid-base indicator strip
3. Some react with active metals to release hydrogen gas
4. React with bases to produce salts and water
5. Conduct electric current
1. Nomenclature:
Binary acid – an acid that contains only 2 different elements; hydrogen and one of the more electronegative elements.
HF, HI, HBr, HCl – starts with hydro then name of second element and ends with ic
Hydrofluoric, hydroiodic, hydrobromic, hydrochloric acid
Oxyacid – an acid that is a compound of hydrogen, oxygen and a third element normally a nonmetal.
2. Common Industrial Acids:
Sulfuric – most common used in petroleum refining, metallurgy, fertilization, production of paper, paints, dyes, detergents, automobile batteries.
Nitric – must be dissolved in water to make it more stable. Used in making explosives, rubber, plastic, dyes, pharmaceuticals.
Phosphoric - used for manufacturing fertilizers, animal feed, detergents and ceramics, as a flavoring agent in beverages, cleaning agent for dairy equipment.
Hydrochloric – removes surface impurities on iron and steel, food processing, activation of oil wells, recovery of magnesium from sea water. Commercially called muriatic acid used to clean pools and masonry.
Acetic – called glacial acetic acid (ethanoic acid) used to manufacture plastic and food supplements. used every day as vinegar.
B. Bases
Properties:
1. Taste bitter
2. Change color of acid-base indicators
3. Feel slippery (soapy)
4. React with acids to produce salts and water
5. Conduct electric current
Nomenclature:
Most are ionic compounds containing metal cations and the hydroxide anion, OH.
Common bases:
Sodium, calcium, barium, strontium, potassium hydroxides, and ammonia
15.1 Acid-Base Titration and pH
A. Ionization constant of water
Kw = [H3O+] [OH-] where [1.0 x 10 -7] [1.0 x 10 -7] = 1.0 x 10 -14
If [H3O+] > [OH-] then it is acidic
If [OH-] > [H3O+] then it is basic
Using the pH scale
1. pH = -log [H3O+]
If using the Kw value of [H3O+] = 1.0 x 10 -7 substitute this into the equation and you will have:
pH = -log [1.0 x 10 -7] = 7.0
Acidic if pH < 7.0 or [H3O+] > 1.0 x 10 -7 otherwise it is basic
2.pOH = -log [OH-]
If using the Kw value of [OH-] = 1.0 x 10 -7 substitute this into the equation and you will have:
pOH = -log [1.0 x 10 -7] = 7.0
3.Therefore: pH + pOH = 14
B. Calculations involving pH
1. Calculating from a base
[H3O+] = 1.0 x 10 -14
[OH-]
Then substitute this into pH = -log [H3O+]
A. Acids
Examples:
Sour milk – lactic acid
Vinegar – acetic acid
Carbonated beverages – phosphoric acid
Citrus fruits – citric acid
Apples – malic acid
Grapes – tartaric acid
Properties:
1. Have a sour taste
2. Will change the color of acid-base indicator strip
3. Some react with active metals to release hydrogen gas
4. React with bases to produce salts and water
5. Conduct electric current
1. Nomenclature:
Binary acid – an acid that contains only 2 different elements; hydrogen and one of the more electronegative elements.
HF, HI, HBr, HCl – starts with hydro then name of second element and ends with ic
Hydrofluoric, hydroiodic, hydrobromic, hydrochloric acid
Oxyacid – an acid that is a compound of hydrogen, oxygen and a third element normally a nonmetal.
2. Common Industrial Acids:
Sulfuric – most common used in petroleum refining, metallurgy, fertilization, production of paper, paints, dyes, detergents, automobile batteries.
Nitric – must be dissolved in water to make it more stable. Used in making explosives, rubber, plastic, dyes, pharmaceuticals.
Phosphoric - used for manufacturing fertilizers, animal feed, detergents and ceramics, as a flavoring agent in beverages, cleaning agent for dairy equipment.
Hydrochloric – removes surface impurities on iron and steel, food processing, activation of oil wells, recovery of magnesium from sea water. Commercially called muriatic acid used to clean pools and masonry.
Acetic – called glacial acetic acid (ethanoic acid) used to manufacture plastic and food supplements. used every day as vinegar.
B. Bases
Properties:
1. Taste bitter
2. Change color of acid-base indicators
3. Feel slippery (soapy)
4. React with acids to produce salts and water
5. Conduct electric current
Nomenclature:
Most are ionic compounds containing metal cations and the hydroxide anion, OH.
Common bases:
Sodium, calcium, barium, strontium, potassium hydroxides, and ammonia
15.1 Acid-Base Titration and pH
A. Ionization constant of water
Kw = [H3O+] [OH-] where [1.0 x 10 -7] [1.0 x 10 -7] = 1.0 x 10 -14
If [H3O+] > [OH-] then it is acidic
If [OH-] > [H3O+] then it is basic
Using the pH scale
1. pH = -log [H3O+]
If using the Kw value of [H3O+] = 1.0 x 10 -7 substitute this into the equation and you will have:
pH = -log [1.0 x 10 -7] = 7.0
Acidic if pH < 7.0 or [H3O+] > 1.0 x 10 -7 otherwise it is basic
2.pOH = -log [OH-]
If using the Kw value of [OH-] = 1.0 x 10 -7 substitute this into the equation and you will have:
pOH = -log [1.0 x 10 -7] = 7.0
3.Therefore: pH + pOH = 14
B. Calculations involving pH
1. Calculating from a base
[H3O+] = 1.0 x 10 -14
[OH-]
Then substitute this into pH = -log [H3O+]
ACIDS Strongest to weakest
HClO4 perchloric acid
HI hydroiodic acid
HBr hydrobromic acid
HCl hydrochloric acid
HNO3 nitric acid
H2SO4 sulfuric acid (diprotic)
CH3COOH acetic acid
HCOOH formic acid
HF hydrofluoric acid
HCN hydrocyanic acid
HNO2 nitrous acid
HSO4- hydrogen sulfate ion
BASES Strongest to weakest
NaOH sodium hydroxide
KOH potassium hydroxide
Ba(OH)2 barium hydroxide
NH3 ammonia
CH3NH2 methylamine
C5H5N pyridine
HClO4 perchloric acid
HI hydroiodic acid
HBr hydrobromic acid
HCl hydrochloric acid
HNO3 nitric acid
H2SO4 sulfuric acid (diprotic)
CH3COOH acetic acid
HCOOH formic acid
HF hydrofluoric acid
HCN hydrocyanic acid
HNO2 nitrous acid
HSO4- hydrogen sulfate ion
BASES Strongest to weakest
NaOH sodium hydroxide
KOH potassium hydroxide
Ba(OH)2 barium hydroxide
NH3 ammonia
CH3NH2 methylamine
C5H5N pyridine