Naming Ionic Compounds. Monatomic Ions Made from a single atom gaining or losing an electron (based...
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Transcript of Naming Ionic Compounds. Monatomic Ions Made from a single atom gaining or losing an electron (based...
Monatomic IonsMonatomic IonsMade from a single atom gaining or
losing an electron (based on valence electrons) Element Oxidation #
Li +1Be +2O -2F -1
Writing ions- write symbol, write charge as a superscript
Ex. Al+3
Writing Ionic CompoundsWriting Ionic CompoundsMade of two parts – cation &
anionName the cation first (typically a
metal) just as it appears on periodic table
Na+ SodiumCa+2 Calcium
Writing Ionic Compounds Writing Ionic Compounds with Transition Metalswith Transition MetalsMost transition metals have more
than one oxidation numberIf the transition metal has more
than one oxidation number, you must represent it with a Roman Numeral in its name
Transition Metals to knowTransition Metals to knowScandium column – always +3,
no Roman Numeral neededF-block – always +3, no Roman
Numeral neededAg – always +1, no Roman
Numeral neededCd & Zn – always +2, no Roman
Numeral needed
Transition Metals to know Transition Metals to know (cont.)(cont.)Sn & Pb – either +2 or +4Sn & Pb and all other transition
metal’s oxidation # will be determined by “uncrossing the criss-cross”
(I’ll explain in a minute)Examples:
Fe+2 Iron II Fe+3 Iron IIIAl+3 Aluminum Cu+2 Copper IICu+ Copper I Zn+2 Zinc
Writing Ionic Compounds Writing Ionic Compounds (cont.)(cont.)Write the anion next (typically a
nonmetal)Change the ending to –ide
Cl- , chlorine chlorideO-2 , oxygen oxide
**If the anion is a polyatomic ion, the name stays the same**
Writing Ionic Compounds Writing Ionic Compounds PracticePracticeNaClFeSAlCl3Na2O
Al2O3
CuO
Sodium ChlorideIron II SulfideAluminum
ChlorideSodium OxideAluminum OxideCopper II Oxide
How to determine the How to determine the Oxidation Number of Oxidation Number of Transition MetalsTransition MetalsIdentify metal as a Transition with
multiple oxidation numbersUncross the “criss-cross”If nothing to uncross, identify the
charge of the anion (they will always only have one oxidation number), charges have been simplified
Transition metal charge is the same as anion charge (just +)
How to determine the How to determine the Oxidation Number of Oxidation Number of Transition Metals (cont.)Transition Metals (cont.)Ex. #1
Fe2O3
+3 -2
Fe2O3
Iron III Oxide
How to determine the How to determine the Oxidation Number of Oxidation Number of Transition Metals (cont.)Transition Metals (cont.)Ex.#2
FeS**No subscripts to show charge, so
ID anion chargeS = -2, therefore Fe must be +2 Name = Iron II SulfideEx.#3
CuOName = Copper II Oxide
Writing an Ionic FormulaWriting an Ionic FormulaIdentify the charge on each part
of the compound (cation and anion)
Remember…the sum of the oxidation numbers MUST EQUAL ZERO
Add subscripts to balance charges (can be done with criss-cross method)
Writing an Ionic Formula Writing an Ionic Formula (cont.)(cont.)Ex. #1 = Calcium Chloride
Ions Ca = +2 Chlorine = -
1
+2 -1 Ca ClFormula = CaCl2
(Remember…never write 1’s)
Writing an Ionic Formula Writing an Ionic Formula (cont.)(cont.)Ex.#2 = Magnesium Oxide
Ions Mg = +2 O = -2
Use “criss-cross” Mg2O2
**Simplify when possible MgO
Extra RuleExtra RuleCan’t change a Polyatomic Ions
subscripts (if you need multiple polyatomics, you must put the ion symbol in brackets)Ex. PO4 = has a -3 charge
Ca = has a +2 chargeFormula = Ca3(PO4)2
Changes to Polyatomic Changes to Polyatomic IonsIonsWe must know the “root”
polyatomic ion (the ones on our list)
Oxygens can either be added or subtracted from the formula we know
When that happens, the polyatomic ion name changes