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
IONIC COMPOUNDS
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
3.3.2
Identify the common polyatomic ions and write chemical formulas of polyatomic ionic compounds.
The formulas with their charges of the most common ions will be provided on the data sheet.
Students are expected to know their names and deduce the chemical formulas.
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
Type 4.
Acids
Acid an ionic compound whose cation is a hydrogen ion H+
a substance that produces H+ ions in solution (must be in aqueous state)
Aqueous = dissolved in water
3.3.3
Write the chemical formula and name for molecular compounds and common acids
BINARY ACIDS

no oxygen in anion (not polyatomic anion)
CHEMICAL NAME
Recognize the formula starts with H and the anion has NO OXYGEN
 Add prefix “HYDRO”
 Change –IDE (I Don’t have Oxygen) of the anion to –IC (tastes sour)
 Add “ACID” at the end
OXOACIDS (Polyatomic Acids) combinations of oxygen with another element

CHEMICAL NAME
Recognize the formula starts with H and the anion HAS OXYGEN
 Do NOT add prefix “HYDRO”
 Change –ATE (I Don’t have Oxygen) of the anion to –IC (tastes sour)
 Add “ACID” at the end
ORGANIC ACIDS (Carboxylic acid) – have COOH group
Table 3.3 List of the common acids arranged by type.
Formula
Acid Name
Comments
hydrogen chloride
HCl
hydrochloric acid
stomach acid
hydrogen nitrate
HNO3
nitric acid
strong acid
hydrogen carbonate €
H2CO3
carbonic acid
weak acid
hydrogen sulfate
€
H2SO 4
sulfuric acid
battery acid
hydrogen phosphate€
H3 PO 4
phosphoric acid
hydrogen acetate €
CH3 COOH
Type
Ionic Name
BINARY
OXOACIDS
ORGANIC
€
€
acetic acid
in colas
vinegar
MOLECULAR COMPOUNDS
Molecular Compounds
NON-METAL ATOMS held together by COVALENT BONDS
Organic Compounds
complex carbon compounds made by living organisms
All carbon containing compounds except: CO, CO2, and carbonates (CO32– )
Inorganic Molecules
all other molecular compounds
 Type 1. Inorganic Molecular Compounds
General Rules for Naming

Order of elements: generally left to right (→) and bottom to top (↑) in Periodic Table (by electronegativity)

Use PREFIXES to show the number of atoms of each element in the compound
o DO not use prefix for first element if there is only 1
o drop the “A” at the end of the prefix for OXIDES

Second element is named like an anion (ends in –IDE)
PREFIXES
1=
2 = DI
3 = TRI
4 = TETRA
5 = PENTA
7 = HEPTA
8 = OCTA
9 = NONA
10 = DECA
MONO
6 = HEXA
CO
carbon monoxide
P2O5
diphosphorus pentoxide
CO2
carbon dioxide
P4O8
NI3
nitrogen triiodide
tetraphosphorus octoxide
 Type 2. Traditional Names
→ exceptions to the General Rules
H2O
water
rather than
dihydrogen monoxide
NH3
ammonia
rather than
nitrogen trihydride
or
hydrogen hydroxide
 Type 3. Organic Compounds
have different naming systems for different types of molecules
C6H12O6
glucose
 Hydrocarbons
blood sugar
all sugars end in –OSE (lactose, sucrose)
contain ONLY hydrogen and carbon atoms;
use different prefixes than inorganic molecules
CH4
methane
C3H8
propane
bunsen burners, barbeques
C8H18
octane
gasoline (cars)
C6H6
benzene
ring found in PCBs, PAHs, DDT, and other toxic chemicals