Ch 5 - Ionic CompoundsCh 5 - Ionic Compounds
Naming & Writing Formulas
RememberRemember
• In an ionic compound– 1st element is a + metal ion– 2nd element is a – nonmetal ion
• Naming is EASY PEASY!– 1st element’s name doesn’t change– 2nd element’s name ends in –ide – Transition metals need to show Roman Numeral– polyatomic ions keep their own names
Naming Nonmetal AnionsNaming Nonmetal Anions
Transition Metals – Use Systemic NameTransition Metals – Use Systemic Name
What are Polyatomic Ions• Groups of elements that act as a group• The charge is on the entire group• NEVER change formula of polyatomic ions• Put them in parenthesis if need be.
is written as SO4 -2
Ex. compounds: BaSO4 Barium Sulfate Fe2(SO4)3 Iron III Sulfate
Common Polyatomic Ions
ExamplesExamples1. Regular
NaF – Sodium Fluoride
CaO – Calcium Oxide
2. Transitional MetalsFeCl3 – Iron III Chloride (Fe+3 because 3 Cl- in formula)
CuI – Copper I Iodide (Cu+1 because one I- in formula)
3. Polyatomic Ions
BaSO4 – Barium Sulfate
NH4OH – Ammonium Hydroxide
Mixed Practice
1.1. BaIBaI22
2.2. Ca(OH)Ca(OH)22
3.3. FeCOFeCO33
4.4. NaNa22CrCr22OO77
5.5. Cu(ClOCu(ClO44))22
1.1. Barium iodideBarium iodide
2.2. Calcium hydroxideCalcium hydroxide
3.3. Iron (II) carbonateIron (II) carbonate
4.4. Sodium dichromateSodium dichromate
5.5. Cupric perchlorateCupric perchlorate
Writing Ionic FormulasWriting Ionic FormulasCompounds are neutral: +ions & – ions have to balanceSteps
•Write the + ion first•Write the – ion second•Compare oxidation numbers (charges)
-If the same, you are done-If different, criss-cross as subscripts-Never change polyatomic ions (use parenthesis if needed)
Formula of Ionic CompoundsFormula of Ionic Compounds
Al2O3
Al3+ O2-
CaBr2
Ca2+ Br-
Na2CO3
Na+ CO32-
Try it out…Try it out…
• Write the formula for a combination of these ions:
Try it OutTry it Out
• Write the formula of these ionic compounds:
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