COMPOUNDS

• There's no such thing as "chemical-free"
• Chemical


  A substance that can be represented using a fixed chemical formula and possess characteristic properties
• Compound


  A type of chemical which is defined as a substance composed of atoms of two or more elements chemically united in fixed proportions
• Water and air are considered "chemicals"
• Metallic Bond


  • Forms among metallic substances, a direct consequence of attractive electrostatic forces between the negatively charged sea of delocalized electrons and the positively charged metal ions
• Covalent Bond


  • Electrons involved in bond formation are shared by the two atoms bonded with one another
• Ionic Bond


  • Involves the complete transfer of valence electron(s) between atoms, usually occurs between a metal and a nonmetal
• Coordinate Covalent Bond


  • Also known as a dative bond, both electrons are supplied by one of the two bonded atoms
• Types of Chemical Bonds

  • Metallic Bond
  • Covalent Bond
  • Ionic Bond
  • Coordinate Covalent Bond
• Naming Binary Covalent Compounds


  1. The first element in the chemical formula is named first using the name of that element

  2. The second element in the chemical formula is named as if it is an anion

  3. Indicate the number of that element using the appropriate prefix

  4. The prefix "mono-" is never used in denoting the number of the first element

  5. If the name of the element starts with a vowel, drop the "a" or "o" in the prefix
• Writing Chemical Formula of Binary Covalent Compounds

  1. Identify the chemical symbol of the element

  2. Take note of the prefix used for each element, and write the corresponding number as a subscript of that element

  3. When writing the chemical formula, write the less electronegative element first
• Prefixes for denoting number of atoms

  • mono-
  • di-
  • tri-
  • tetra-
  • penta-
  • hexa-
  • hepta-
  • octa-
  • nona-
  • deca-
• Naming Binary Ionic Compounds

  1. The cation is always named first, while the anion is always named second

  2. Monoatomic cations are named as if they are elements, while the monoatomic anion takes the root of the element name + "-ide"

  3. Polyatomic cations and anions have special and unique names

  4. The prefixes used in the nomenclature of covalent compounds are not usually used in the nomenclature of ionic compounds
• Naming Type I Binary Ionic Compounds

  1. The cation is always named first, while the anion is always named second

  2. Monoatomic cations are named as if they are elements, while the monoatomic anion takes the root of the element name + "-ide"

  3. Polyatomic cations and anions have special and unique names

  4. The prefixes used in the nomenclature of covalent compounds are not usually used in the nomenclature of ionic compounds
• Naming Type II Binary Ionic Compounds

  1. The cation is always named first, while the anion is always named second

  2. The cation is named using the element name followed by the Roman numeral in parentheses to indicate the oxidation state
• Ions


  • O 4 2– permanganate
  • CrO 4 2– chromate
  • O 2 2– peroxide
  • Cr 2 O 7 2– dichromate
  • S 2 O 3 2– thiosulfate
  • AsO 4 3– arsenate
  • ClO – hypochlorite
  • PO 3 3– phosphite
  • ClO 2 – chlorite
  • PO 4 3– phosphate
  • ClO 3 – chlorate
  • HPO 4 2– hydrogen phosphate/biphosphate
  • ClO 4 – perchlorate
  • H 2 PO 4 – dihydrogen phosphate
• Chemical Formula


  • NaCl sodium chloride
  • NH 4 Br ammonium bromide
  • Ba(OH) 2 barium hydroxide
  • (NH 4 ) 2 SO 4 ammonium sulfate
• One of the most common mistakes committed when naming ionic compounds is the use of prefixes used for naming binary covalent compounds. Keep in mind that those prefixes are NEVER used when naming ionic compounds.
• Type II Binary Ionic Compounds


  • Rule 1: The cation is always named first, while the anion is always named second.
  • Rule 2: In naming the cation using the systematic method, identify the oxidation state of the cation, and write the oxidation state (in roman numeral) adjacent to the name of the cation
  • Rule 3: In naming the cation using the stock system, identify the oxidation state of the cation. If the oxidation state of the cation is less than the other oxidation state, the cation is named as the element root name + – ous. On the other hand, if the oxidation state of the cation is greater than the other oxidation state, the cation is named as the element root name + – ic.
  • Rule 4: Name the monoatomic anion by taking the root of the element name + – ide. Use corresponding names for polyatomic anions.
  • Rule 5: The prefixes used in the nomenclature of covalent compounds are not usually used in the nomenclature of ionic compounds.
• Metal ion


  • Pb 2+ plumbous
  • Pb 4+ plumbic
  • Fe 2+ ferrous
  • Fe 3+ ferric
  • Co 2+ cobaltous
  • Co 3+ cobaltic
  • Cu + cuprous
  • Cu 2+ cupric