Chapter 20Acids and Bases
Section 20.1Describing Acids and Bases
OBJECTIVES:
Name an acid or base, when given theformula.
Acids
Bases
Properties of acids
Taste sour
Conduct electricity.
Some are strong, other are weak electrolytes
React with metals to form hydrogen gas.
React with bases to form water and an ioniccompound (salt).
Turns blue litmus paper red/pink.
Properties of bases
React with acids to form water and an ioniccompound (salt).
Taste bitter.
Feel slippery (don’t try this either).
Can be strong or weak electrolytes.
Turns red litmus paper blue
Electrolytes
Types of AcidsAll have an H
Binary Acids (Contains an H+ and anelement)
Ex. HCl, HF, HI, H2S
Tertiary Acids (Contains an H+ and apolyatomic acid)
Ex. H3(PO4), H2(SO4)
Naming Binary Acids
1. Use prefix hydro
2. Use root of negative element and usesuffix –ic
3. Add acid
Example:
HCl hydrochloric acid
H2Shydrosulfuric acid
Writing Formulas for Binary Acids
1. Write the symbol H+
2. Write the symbol for the other element withcharge.
3. Criss-cross the charges to determine thesubscripts.
Example:
Hydrofluoric acid HF
Hydronitric acid H3N
Naming Tertiary Acids
1. Use the root of negative element
2. If the polyatomic ion ends with “ate”change the ending to “ic” and add the wordacid.
***Remember, you ate something“ICKYYY!!!:
3. If the polyatomic ion ends with “ite” changethe ending to “ous” and add the word acid.
Writing Formulas for Tertiary Acids
Write the symbol H+
2. Write the symbol for the other polyatomic ion withcharge.
3. Criss-cross the charges to determine the subscripts.
Example:
Sulfuric AcidH2(SO4)
Nitrous acidH(NO2)
Naming Bases (Have an OH)
1. Name the metal (If it is a transitional metal,indicate the charge in parenthesis by uncrossingthe subscript)
2. Name hydroxide
Example:
Mg(OH)2Magnesium Hydroxide
Cu(OH)2Copper (II) Hydroxide
Writing Formulas for Bases
1. Write the symbol for the metal with charge.
2. Write the symbol for hydroxide (OH-)
3. Criss-Cross the charges.
Examples:
Tin (IV) Hydroxide Sn(OH)4
Sodium Hydroxide Na(OH)