Naming Compounds Involving Transition Metals and Polyatomic Ions.

Naming Compounds Involving Transition Metals

and Polyatomic Ions

Transition Metals

• The transition metals and the metals to the right of them generally form more than one ion. We call these elements multivalent.

• The charges on the multivalent elements' ions are not always predictable, although some patterns do exist.

• Consequently, you won't be expected to predict these, although you will be expected to work with them.

Ionic Compounds Involving Transition Metals

• Roman numerals are used in the name of the transition metal in the compound to show the valence on the cation.

• Examples:• Mn+4 = Manganese(IV) OR Mn+5 =

Manganese(VI)• Fe+2 = Iron(II) OR Fe Iron(III)• Cu+1 = Copper(I) OR Cu+2 = Copper(II)

Examples of Transition Metals

• Iron(II)• Iron(III)• Copper(I)• Copper(II)• Manganese(II)• Manganese(IV)

• Fe +2

• Fe +3

• Cu+1

• Cu+2

• Mn+2

• Mn+4

Steps to Naming the Ionic Compounds1. Separate the two elements-metal and non-metal2. Add 1’s with the element that has no number3. Cross-over from bottom to top4. Add the charges-REMEMBER the first one (metal) is positive and the second (non-metal) is negative5. Make sure the charges match those found on the Periodic Table

**If they do not , MULTIPLY both charges with the same number to find the non-metals true charge.

6. Write the name-the metal stays the same, but the non-metal changes it’s ending to “ide”.

Let’s Practice!

• Name the ionic compound for Fe2O3

• PbO2

Special Cations

Steps to Writing Chemical Formulas

1. Determine the metal and non-metal**Hint-the element with the roman numeral is the metal

2. Write the charges-Look at the roman numeral for the metal’s charge- Look at the Periodic Table for the non-metal’s charge

3. Cross over from top to bottom4. Remove the charge and make each number a subscript5. Simplify the numbers6. Remove any 1’s7. Rewrite using the element symbol and include the subscript

Let’s practice!

• Manganese (IV) Oxide

• Copper(II) phosphide

Polyatomic Ions

• Polyatomic (many atom) ions are covalent molecules with a charge. They behave as if they were a one-atom ion.

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Naming Compounds Involving Polyatomic Ions

• Polyatomic Ions can form ionic or covalent bonds.

• The polyatomic ion is always listed second.• You DO NOT use the ending “ide”