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Ionic Compounds. Naming & Formula Writing. Monatomic Ions. Charged particles composed of one type of atom Cations (+) or anions (-) atoms lose or gain electrons to become stable Oppositely charged ions are attracted to each other and form an ionic bond Ex. Na + Cl - form NaCl.
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Ionic Compounds Naming & Formula Writing
Monatomic Ions • Charged particles composed of one type of atom • Cations (+) or anions (-) atoms lose or gain electrons to become stable • Oppositely charged ions are attracted to each other and form an ionic bond Ex. • Na+ Cl- form NaCl
Binary Compounds • Composed of a cation and an anion • Metal and a nonmetal • Neutral (total + and – charges cancel) • Use subscripts to make charges = 0 • Ions are in smallest whole # ratio • Naming – cation first (name of metal), anion second (name of nonmetal with an “ide” ending
Binary Examples • Lithium and oxygen • Li+ O2- forms Li2O • Lithium oxide • Magnesium and sulfur • Mg2+ S2- forms MgS • Magnesium sulfide
Try the criss cross method! • If the charges equal zero, no subscripts are required. • If they don’t equal zero, use subscripts to make the total charge zero. • Strontium and phosphorus • Sr2+ P3- • Sr3P2 • Strontium phosphide
You try it! • Potassium and bromine • KBr potassium bromide • Calcium and phosphorus • Ca3P2 calcium phosphide • Aluminum and chlorine • AlCl3 aluminum chloride • Sodium and nitrogen • Na3N sodium nitride
Characteristics of Ionic Compounds • Electrically neutral • High melting point • Brittle solids • Water soluble • Solutions are good electrical conductors
Binary Compounds with Transition Metals • Transition metals may have more than one charge • When naming, must indicate charge with a Roman Numeral – look at what it is bonded with to determine • Ex. CuCl2 copper (II) chloride CuCl copper (I) chloride
Formula Writing with Transitions • The Roman numeral in the name tells the charge of the transition metal. • Ex. Chromium (III) oxide • Cr2O3 • Exceptions: Zn & Cd are always 2+ and silver is always 1+ so no Roman numeral is used
Other Exceptions • Lead and Tin are not transition metals but they act like them – can have more than one charge. • Therefore, a Roman numeral is used when naming ionic compounds containing them. • SnO2 tin (IV) oxide
Now you try it! • Iron (III) oxide • Fe2O3 • Nickel (II) nitride • Ni3N2 • Cu2S • Copper (I) sulfide • Co3P2 • Cobalt (II) phosphide
STOP!!! • DON’T GO ANY FURTHER!!
Tertiary Ionic Compounds • Composed of either a cation or anion and a polyatomic ion • Polyatomic ions are covalently bonded atoms that behave as a charged particle. (most are anions) • When naming, use same naming rules except give the polyatomic its same name
Tertiary Example • Calcium and phosphate • Ca2+ PO43- form Ca3(PO4)2 • Calcium phosphate • Note that when more than one of a polyatomic ion is required in the formula, the PAI is in () with the subscript outside the ()
Try these! • Aluminum and acetate • Al(C2H3O2)3 • Magnesium and sulfate • MgSO4 • Copper (II) phosphate • Cu3(PO4)2 • Iron (II) carbonate • FeCO3 • Ammonium and nitrite • NH4NO2 • Nickel (II) hydroxide • Ni(OH)2