Nomenclature

Binary Ionic Compounds

Naming• Metal cation is always written first followed by the non-metal anion.• The name of the metal is stated in full and the name of the non-

metal ion is given the suffix –ide. • Must contain only two kinds of atoms. Eg. Al2O3

- Aluminum Oxide

Formula• Write symbols in order.• Determine the charges on each type of ion making up the

compound. (valence)• Crisscross the valences making them subscripts and then balance the

charges to determine the simplest ratio. (formula unit)• Remove subscripts of 1.• The net charge must equal zero. Eg Mg2+ + Cl- = MgCl2

Naming Transition Metals (Multivalent)

Naming• The name of a metal ion includes the charge of the ion in

brackets as Roman numerals. It is also known as the Stock system. Eg. Copper (I) chloride CuCl(s) and Copper (II) chloride CuCl2 (S).

Formula• Figure out the equivalent negative charge on the ion to yield

a net charge of zero. Write the name of the charge in brackets in Roman numerals after the metal. Eg. MnO2

Manganese (IV) oxide. • If the metal is not specified in a name, assume the most

common charge.

p92 Table 2- Classical Method

Molecular Compounds

Naming• Two non-metals can combine to form more than one

compound. Eg. N2O, NO, NO2, etc.• A greek prefix is attached to the name of each

element in the binary compound indicating the number of atoms of that element in the molecule.

• If there is only one of the first type of element, leave out the “mono” prefix.

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p95 Table 3- Common Polyatomic Ions

Naming Polyatomic Ions

Naming• Polyatomic ions that include oxygen are called oxyanions.

• Write the name of the metal cation.• For the second part, there are 4 polyatomic ions that can be formed

from combinations with oxygen. Eg chlorine and oxygen– ClO- hypochlorite– ClO2

- chlorite– ClO3

- chlorate– ClO4

- perchlorate– The suffixes and prefixes vary according to the number of oxygen atoms.

Formula• The crisscross method can also be used to predict the

formula.

Hydrates• A compound that contains water as part of its ionic

crystal structure or a compound that decomposes to an ionic compound and water vapor when heated. Therefore water is loosly held in the compound.

Eg. CuSO4.5H2O copper (II) sulfate pentahydrate

• Prefixes for hydrates

Naming Acids

1. Binary Acids• Classically: Hydro-stem-ic acid= Hydrochloric acid• IUPAC: HCl (g)= hydrogen chloride, HCl (aq)= aqueous hydrogen

chloride when dissolved in water. p99 Table 6

Note: suffix of -ide2. Polyatomic acids (Oxyacids)

- An acid containing oxygen, hydrogen and a third element. More simply, an oxyanion and hydrogen.

• Drop the “hydro” Substitute: “ic”= -ate “ous” = -itep99 Table 7&8

Formula for Acids

1. Figure out the names of the ions involved

2. Symbols or formulas

3. Ratio using crisscross method

Naming Bases

• All aqueous solutions of ionic hydroxides are bases. Eg. NaOH(aq) aqueous sodium hydroxide.

Chapter 3: Chemical Compounds and Bonding

3.1 Classifying Chemical Compounds

Follow along on your notes. Feel free to make notes on your notes!

Elements

• There are about 90 naturally occurring elements.

• Most are not found as pure elements. • The majority of elements are found combined

with other elements to form compounds. • Gold, silver and platinum are rare examples of

metals found in elemental form (precious metals).

Classification Systems

• Since the 90 elements can form thousands of different compounds, classification systems have been developed.

• The classification of compounds is based on their properties to help our understanding of compounds.

• Example: melting point, boiling point, hardness, etc.

Properties of Ionic and Covalent Compounds

• Chart is on page 67 of your textbook.

What is a crystalline solid? What does it look like?

• A crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions.

Thought Lab: Ionic or Covalent?

With the person sitting next to you, take a look at the following chart (also on page 68 of your textbook).

See if you can figure out what compound belongs with what sample number.

The compounds used were:EthanolCarbon tetrachlorideGlucoseTable salt (sodium chloride)WaterPotassium permanganate

Experimental Results

water covalent

NaCl ionic

Potassium permanganate ionic

glucose covalent

Carbontetrachloride covalent

ethanol covalent

What is Bonding?

Chemical Bonds

• forces that attract atoms to each other to form compounds

• involves the interactions of valence electrons between atoms

• usually the bond forms a compound that is more stable than the atoms individually.

Ionic Bonds

• a chemical bond formed when one atom loses valence electron(s) an another atom gains electron(s).

• occurs between metal and nonmetal atoms

Covalent Bonds

• form when two atoms share valence electrons• occurs between two non metal atoms

Electronegativity (EN)

• a measure of an atoms ability to attract electrons in a chemical bond.

• a property of an atom involved in a bond

How can we use electronegativity to predict bond type?

When two atoms form a bond the difference in electronegativity (ΔEN) can help to determine the bond type.

| | | 0 0.5 1.7

3.3

Examples

• HCl3.16- 2.2= 0.96 Polar Covalent• CrO3.44- 1.66= 1.78 Ionic• Br2

2.96-2.96= 0 Covalent

Homework

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