A lot of chemicals have common names as well as the proper IUPAC name.
Common name = “nickname”
Proper name = systematic name developed by methods of the International Union of Pure and Applied Chemists
Though chemicals have both a common and proper name, some chemicals are called exclusively by their common name:
H2O water, not dihydrogen monoxide
NH3 ammonia, not nitrogen trihydride
COMPOUNDS FORMED FROM IONS Na+ + Cl- NaCl CATION + ANION COMPOUND A neutral compound requires equal number of (+) and (-) charges. Let’s learn how to name the ions. Then, we can name their compounds.
Predicting Charges on Monatomic Ions KNOW THESE !!!! +1 +2 +3 +4 -3 -2 -1 0 Cd+2
Naming Monatomic Cations: Rule – The metal ion has the same name as the element but add “ion” after
Naming Transition Cations: Rule – The transition metal ion has the same name as the element but add the charge value in Roman Numerals after:
This happens with the following elements:
Fe = Iron Fe2+ = Iron (II) ion
Fe = Iron Fe3+ = Iron (III) ion
Name each of the following monatomic cations:
Writing the transition ions this way helps to differentiate between the different “flavors” the ions come in
Examples of Older Names of Cations formed from Transition Metals (you do not have to memorize these)
Naming Monatomic Anions: Rule – When a nonmetal forms an ion, it is named: element stem name + “-ide” + ion
CaO = Calcium cation + Oxygen anion calcium oxide
LiF = Lithium + Fluorine Lithium Fluoride
Name each of the following monatomic anions:
Rule – the cation goes FIRST the anion SECOND The naming uses the individual ion naming system: LiBr CaBr 2 MgO KCl BeS
Ionic Naming Practice NaCl CaCl 2 MgO Al 2 O 3 FeBr 2 CuCl SnO 2 Fe 2 O 3 Hg 2 S
Ionic Naming Practice NaCl CaCl 2 MgO Al 2 O 3 FeBr 2 CuCl SnO 2 Fe 2 O 3 Hg 2 S Sodium chloride Calcium chloride Magnesium oxide Aluminium oxide Iron (II) Bromide Copper (I) Chloride Tin (IV) Oxide Iron (III) Oxide Mercury (II) Sulfide [notice the subscript number under the oxygen = the number for Iron’s Roman Numerals]
Ionic Naming Warm Up NaBr BeCl 2 K 2 O Al 2 S 3 AgBr 2 CdCl 2 SnO FeO CuS
Ionic Naming Warm Up NaBr BeCl 2 K 2 O Al 2 S 3 AgBr 2 CdCl 2 SnO FeO CuS Sodium bromide Beryllium chloride Potassium oxide Aluminium sulfide Silver Bromide Cadmium (II) Chloride Tin (II) Oxide Iron (II) Oxide Copper (II) Sulfide
1. Cation first, then anion 2. Monatomic cation = elemental name Ca 2+ = calcium ion 3. polyatomic anion = name of polyatomic CO32 = carbonate Thus CaCO3 = calcium carbonate Overview of Naming Ternary Ionic Compounds: Take Home Message: Same method as with binary ionics except a polyatomic anion is in place of the monatomic anion!
we’ve learned to name Chemicals Now, let’s write some formulas!
Ternary Ionic Formulas Calcium Sulfate Ca2+ and SO4-2 CaSO4 Iron (III) hydroxide Fe+3 and OH- Fe(OH)3 Ammonium carbonate NH4+ and CO3–2 (NH4)2CO3 The (2+) and (2-) charges cancel each other out So, we need one of each The (3+) needs (3-) to cancel but OH is only a (1-) So, we need three OH ions The (2-) needs (2+) to cancel but NH4 is only a (1+) So, we need two NH4 ions
Learning Check 1. aluminum nitrate a) AlNO3 b) Al(NO)3 c) Al(NO3)3 2. copper (II) nitrate a) CuNO3 b) Cu(NO3)2 c) Cu2(NO3) 3. Iron (III) hydroxide a) FeOH b) Fe3OH c) Fe(OH)3 4. Tin (IV) hydroxide a) Sn(OH)4 b) Sn(OH)2 c) Sn4(OH)
Ionic Formula Writing Going in Reverse of Naming
Write each ion separately
Don’t show ion charges in the final formula
Overall charge of compound must equal zero
If charges on the cation and anion cancel each other just write one of each ion
If not, you need more than one of either the cation or anion
Use subscripts to balance charges
Use parentheses to show more than one of a particular polyatomic ion.
1. Cation first, then anion 2. Monatomic cation = elemental name calcium = Ca2+ 3. monatomic anion = “-ide” name sulfide = S2- Thus calcium sulfide = CaS Overview of Formula Writing Steps: Take Home Message: It’s just that easy! But, beware the charge balance!!!!!!
You Try it: Write these out on your notes Write the formula: Potassium bromide Barium fluoride Copper (II) oxide Calcium nitride Aluminum carbonate Beryllium hydroxide KBr K+ & Br- BaF2 Ba2+ & F- CuO Cu2+ & O2- Ca3N2 Ca2+ & N3- Al2(CO3)3 Al3+ & CO32- Be(OH)2 Be2+ & OH- *Notice any relationship between the charges of the anions and the subscripts on the cations? Vice-versa?