Naming Ionic Compounds Physical Science

Example: Sugar (Glucose) TYPES OF FORMULAS Example: Sugar (Glucose) Molecular formula - true formula; shows the actual number of atoms in a compound C6H12O6

Example: Sugar (Glucose) TYPES OF FORMULAS Example: Sugar (Glucose) Empirical formula - the simplest whole number ratio (reduce all numbers evenly) C6H12O6 → CH2O

Example: Sugar (Glucose) TYPES OF FORMULAS Example: Sugar (Glucose) Structural formula - shows the arrangement of atoms and bonds in a picture, chain or shape

Naming Ions Cations (+ ions) = metal ions Examples: Always named 1st. Name does not change. Examples: Na+1 = sodium Mg+2 = magnesium Ga+3 = gallium

Naming Ions Anions (- ions) = nonmetal ions Examples: Always named 2nd. Change end of name to –ide. Examples: F-1 = fluoride (not fluorine) O-2 = oxide (not oxygen) P-3 = phosphide (not phosphorus)

Polyatomic Ions Polyatomic ion Group of atoms acting as a single ion. Have a net negative or net positive charge. Always treat as an unbreakable group!

Polyatomic Ions Common polyatomic ions (know these!): ammonium = NH4+1 acetate = C2H3O2-1 nitrate = NO3-1 hydroxide = OH-1 carbonate = CO3-2 sulfate = SO4-2 phosphate = PO4-3 These are listed on the back of your periodic table sheet!

Writing names from formulas Write the name of the cation (metal) first. Write the name of the anion (nonmetal) by changing the elements’ ending to -ide. IF you have a polyatomic ion (look at your chart), then write the name as-is. For ions with variable oxidation #’s (transition elements), write the ox. # in parentheses using Roman numerals.

Practice NaBr CuF2 Ag2O3

Naming Ionic Compounds Name the following ionic compounds in your notebook: NaCl = ? K3N = ? BaBr2 = ? MgO = ? CaS = ? Al2Se3 = ? sodium chloride potassium nitride barium bromide magnesium oxide calcium sulfide aluminum selenide

Writing Formulas from Names 1) Identify ions in formula. Cation is written first 2) Figure out charges. They must equal zero! If the charges cancel out, just write the symbols 3) If charges don’t cancel out, use the Criss-cross method. Use parentheses when more than one polyatomic ion is needed. Roman numerals indicate the oxidation #.

Ionic Formulas potassium chloride magnesium nitrate K+ Cl-  KCl copper(II) chloride K+ Cl-  KCl Mg2+ NO3-  Mg(NO3)2 Cu2+ Cl-  CuCl2

Ionic Formulas calcium oxide aluminum chlorate Ca2+ O2-  CaO iron(III) oxide Ca2+ O2-  CaO Al3+ ClO3-  Al(ClO3)3 Fe3+ O2-  Fe2O3

Writing Formulas from Names Write formulas for the following ionic compounds in your notebook. potassium iodide magnesium fluoride calcium sulfide rubidium nitride aluminum bromide strontium oxide K+1 and I-1 Mg+2 and F-1 Ca+2 and S-2 Rb+1 and N-3 Al+3 and Br-1 Sr+2 and O-2 KI MgF2 CaS Rb3N AlBr3 SrO

Writing Formulas With Polyatomic Ions If you need to multiply a poly. ion, use parentheses. Examples: Na+1 and NO3-1 = NaNO3 Mg+2 and NO3-1 = Mg(NO3)2 Al+3 and NO3-1 = Al(NO3)3 Na+1 and CO3-2 = Na2CO3 Mg+2 and CO3-2 = MgCO3 Al+3 and CO3-2 = Al2(CO3)3

Writing Formulas With Polyatomic Ions Write the following ionic formulas in your notebook. Use parentheses when necessary. K+1 and OH-1 = ? NH4+1 and Cl-1 = ? Mg+2 and C2H3O2-1 = ? Al+3 and PO4-3 = ? KOH NH4Cl Mg(C2H3O2)2 AlPO4

Naming Compounds With Polyatomic Ions Polyatomic ions do not change their names in compounds. Example: Ca(OH)2 calcium hydroxide

Naming Compounds With Polyatomic Ions Name the following compounds in your notebook: (NH4)2SO4 Ga2(CO3)3 Li3PO4 NaC2H3O2 Be(NO3)2 ammonium sulfate gallium carbonate lithium phosphate sodium acetate beryllium nitrate

Naming Mixed Ionic Compounds Name the following compounds in your notebook: InBr3 (NH4)2S Sr3N2 KNO3 BaTe ZnCO3 indium bromide ammonium sulfide strontium nitride potassium nitrate barium telluride zinc carbonate