TOPIC 3: CHEMICAL REACTIONS
3.3
IUPAC
Chemical Names and Formulas
International Union of Pure and Applied Chemistry
→ standardized naming system (nomenclature) for every known substance
Compounds substances composed of two or more different elements held together by chemical bonds.
Compounds have no overall charge (neutral charge).
Compounds are generally classified as being either ionic or molecular.
Terms
Binary
2 elements only
IONIC COMPOUND
compound made of cations (usually metals) and anions
Multivalent Metal
metal ions that have more than one possible charge
Oxidation State
actual or apparent charge on an atom in a compound
→ indicated using Roman numerals when naming
Polyatomic
“many atoms” → more than 2 elements
Acid
ionic compound in solution, where cation = H+
MOLECULE
compounds made of ONLY non-metal atoms
Traditional
common, non-systematic (IUPAC), names
Organic
all carbon containing compounds with a few important
Hydrocarbons
contain ONLY hydrogen and carbon atoms
exceptions
Na2O
N2O4
sodium oxide
dinitrogen tetroxide
Cu+
Cu2+
copper (I) ion
copper (II) ion
Fe2+
Pb4+
iron (II) ion
lead (IV) ion
NH4Cl
CaCO3
ammonium chloride
calcium carbonate
HCl
H2SO4
hydrochloric acid
sulfuric acid
H2O
NH3
water
ammonia
C6H12O6
CH3CH2OH
glucose
ethanol
CH4
C3H8
methane
propane
1.3.1 Write the chemical formula and name for ionic compounds, including transition metals with more than one oxidation state
I
Ionic Compounds
CATION + ANION
General Rule for Naming
Name of cation + name of anion
General Rule for Writing Formula
Total Positive Charge = Total Negative Charge
Use the lowest whole number ratio of ions that has no net charge
Subscripts = number of each ion; do not show “1”
Do NOT use prefixes
Type 1. Binary ionic compound (without transition metals)


CHEMICAL NAME from the Chemical Formula → name cation then anion
AlCl3 →
Al Cl →
CaO →
Ca O →
aluminum chloride
calcium oxide
FORMULA from the Chemical Name → balance charges!
CHEMICAL NAME
CATION + ANION
CHEMICAL FORMULA
Ions with charges
sodium chloride
Na+
Cl–
magnesium nitride
Mg2+
N3–
balance charges
(Na+) + (Cl–)
= 1(+1) + 1(– 1) = 0
(Mg2+) + (N3–)
= 3(+2) + 2(–3)
chemical formula in lowest form
Na1Cl1 = NaCl
(Mg2+)3(N3– )2 = Mg3N2
= (+6) + (–6) = 0
Type 2. Multivalent Metals
Ag and Zn
A few transition metals have only one possible charge (oxidation) → Do NOT use Roman numerals
o silver ions are ALWAYS +1 Ag+
AgCl = silver chloride
o zinc ions are ALWAYS +2
ZnCl2 = zinc chloride
Fe, Cu, Sn, Pb
Zn2+
→ Multivalent Metals that have more than one possible oxidation state
→ NEED Roman numerals to show their CHARGE


CHEMICAL NAME
 Determine its CHARGE from the formula
 Write the CHARGE in parentheses using Roman numerals
o 1+ → (I) 2+ → (II)
3+ → (III)
4+ = (IV)
CHEMICAL
FORMULA
Balance charges
(add to 0)
Cation
CHEMICAL NAME
CATION + ANION
FeO
(Fex)1 (O2–)1
1(x) + 1(2–) = 0 →x = 2+
Fe2+
iron (II) oxide
Fe2O3
(Fex)2 (O2–)3
2(x) + 3(2–) = 0
2x – 6 = 0 → x = 3+
Fe3+
iron (III) oxide
FORMULA from the Chemical Name → same as regular binary ionic compounds  balance charges!
CHEMICAL NAME
CATION + ANION
lead (II) nitride
tin (IV) sulfide
CHEMICAL FORMULA
Ions with charges
Pb2+
Sn4+
N3–
S2–
balance charges
(Pb2+) + (N3–)
= 3(+2) + 2(–3)
= (+6) + (–6) = 0
(Sn4+) + (S2–)
= 1(+4) + 2(–2)
= (+4) + (–4) = 0
chemical formula in lowest form
(Pb2+)3(N3– )2 = Pb3N2
Sn1S2 = SnS2
Type 3. Polyatomic Ions
Polyatomic ions are two or more atoms that act as a group and share a total charge.
KEEP THE POLYATOMIC GROUPS TOGETHER – DO NOT CHANGE SUBSCRIPTS
use parentheses when showing more than one ion present in formula
Your data sheets have the formulas and charges of the common polyatomic ions
You are expected to be able to name and use these ions.
Polyatomic Cation there is only 1 NH4+ ammonium ion
Polyatomic Anions – most are combinations of oxygen with another element
 HYDROXIDE
OH–
 -ATES
CO23
carbonate
calcium carbonate = CaCO3
NO-3
nitrate
aluminum nitrate = Al(NO3)3
€
PO3-4
phosphate
sodium phosphate = Na3PO4
€
SO2-4
sulfate
copper (II) sulfate = CuSO4
€
€

CO23
nitrate ion
SiO2-4
PO3-4
silicate ion
CHEMICAL NAME
magnesium hydroxide = Mg(OH)2
NO-3
€
carbonate ion
€
SO2-4
phosphate ion
sulfate ion
ClO-3
chlorate ion
 Hint: Circle any polyatomic anions in the formula
€
 Change
–IDE (I Don’t have €
Oxygen) to –ATE (except for
€ OH = hydroxide)
€

sodium hydroxide = NaOH
FORMULA from the Chemical Name → use (parentheses around groups) when balancing charges!
CHEMICAL NAME
CATION + ANION
iron (III) nitrate
potassium sulfate
ammonium sulfide
CHEMICAL FORMULA
Ions with charges
Fe3+
K+
NH4+
NO3–
SO42–
S2–
balance charges
(Fe3+) + (NO3–)
= 1(+3) + 3(–1)
= (+3) + (–3) = 0
(K+) + (SO42–)
= 2(+1) + 1(–2)
= (+2) + (–2) = 0
(NH4+) + (S2–)
= 2(+1) + 1(–2)
= (+2) + (–2) = 0
chemical formula in lowest form
(Fe3+)1(NO3– )3 = Fe(NO3)3
(K+)2(SO42–)1 = K2SO4
(NH4+)2(S2–)1 = (NH4)2S