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Naming Compounds. Ms. Henry Pre-AP Chemistry. Does the compound consist of a metal and nonmetal?. Then it is an ionic compound!. Naming ionic compounds. Name each ion The positive ion is the cation. It always goes first! The negative ion is the anion. It goes last.
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Naming Compounds Ms. Henry Pre-AP Chemistry
Does the compound consist of a metal and nonmetal? Then it is an ionic compound!
Naming ionic compounds • Name each ion • The positive ion is the cation. It always goes first! • The negative ion is the anion. It goes last.
Naming ionic compounds (con’t) • If the cation has more than one charge possible, write the charge as a Roman numeral after the name. • Example: Lead can have two charges. It can be Lead (II) when it has a Pb2+ or Lead (IV) when it has a Pb4+ • Never use Roman numerals for the anion!
Naming ionic compounds (con’t) • Cross over the charges by using the ion’s charge as the subscript for the other ion.
Naming ionic compounds (con’t) • If the cation has only one charge, then you are finished naming the compound!
Does the compound consist of a nonmetal and a nonmetal? Then it is a molecular compound!
Naming molecular compounds • Name each element • The least electronegative element is named first.
Naming molecular (con’t) • Indicate how many of each are present using prefixes. • Mono (1) di (2) • Tri (3) tetra (4) • Penta (5) hexa (6) • Hepta (7) octa (8) • Nona (9) deca (10)
Naming molecular (con’t) • The first element gets a prefix if there is more than one atom of that element. • Change the ending of the second element to –ide. • The second element always gets a prefix.
Naming molecular (con’t) • If mono- is the first prefix, don’t use it for the first element (carbon monoxide, not monocarbon monoxide).
If the molecular compound starts with an “H” • It is an acid. • There is a special set of rules for naming acids that you will receive when we get to the unit on acids.