Chapter 2Nomenclature

Periodic TablePeriodic Table

Metals Conductors Lose electrons Malleable and ductile

Nonmetals Brittle Gain electrons Covalent bonds

Semi-metals or Metalloids

Alkali Metals

Alkaline Earth Metals

Halogens

Transition metals

Noble Gases

Inner Transition Metals

+1 +2 -1-2-3

Periodic Table Periodic table is organized based on the

properties that elements have in common with one another.

Groups: Elements in the same vertical columns are in the same group have similar chemical properties.

Group 1A: Alkali metals: Li, Na, K, Rb, Cs, Fr Group 2A: Alkaline earth metals: Be, Mg, Ca, Sr, Ba,

Ra Group 7A: Halogens: F, Cl, Br, I, At (astatine) Group 8A: Noble gases: He, Ne, Ar, Kr, Xe, Rn (radon)

Periodic Table Periods: The horizontal rows of elements in the

periodic table are called periods. First period: horizontal row one contains H and He Second period: row two contains Li through Ne Letters in the boxes are the symbols for the

elements Abbreviations are based on the current element

names or the original names. The number above each symbol is the atomic

number (number of protons)

Periodic Table Most of the elements are metals in the periodic

table. Metals: Conduction of heat and electricity,

malleability, ductility, lustrous, form positive ions

Nonmetals: appear in the upper right hand corner of the periodic table except hydrogen. Nonmetals lack the physical properties that characterize the metal, gain electrons in chemical reaction and form negative ions, form covalent bond to each other.

Naming Compounds Binary Compounds: Compounds composed of

two elements Binary Ionic Compounds (Type I): contains a

positive ion (cation) always written first in the formula and a negative ion (anion)

Rules: 1. The cation is always named first and the anion

second2. A monatomic (meaning one atom) cation takes its

name from the name of the element3. A monatomic anion is named by taking the root of

the element name and adding –ide

Naming compounds Two types Ionic - metal and non metal or

polyatomics. Covalent- non-metals.

Ionic compounds If the cation is monoatomic- Name the

metal (cation) just write the name. If the cation is polyatomic- name it. If the anion is monoatomic- name it but

change the ending to –ide. If the anion is poly atomic- just name it.

Covalent compounds Two words, with prefixes. Prefixes tell you how many. mono, di, tri, tetra, penta, hexa, hepta, octa,

nona, deca First element whole name with the

appropriate prefix, except mono. Second element, -ide ending with

appropriate prefix.

Ionic compounds If the cation is monoatomic- Name the

metal (cation) just write the name. If the cation is polyatomic- name it If the anion is monoatomic- name it but

change the ending to -ide If the anion is poly atomic- just name it

from a table.

Ionic Compounds Have to know what ions they form CaS K2S

AlPO4

K2SO4

FeS CoI3

Some Polyatomic Ions (Table 2.3)NH4

+ ammonium SO42- sulfate

CO32- carbonate SO3

2- sulfite

HCO3- bicarbonate NO3

- nitrate

ClO3- chlorate NO2

- nitrite

Cr2O72-

dichromate SCN- thiocyanate

CrO42- chromate OH- hydroxide

2.7

Naming compounds Binary Ionic Compounds (Type II): Metals that

form more than one type of positive ion. Fe2+ and Fe3+

Transition metals form several positive oxidation states

Charge on the metal ion must be specified Roman numeral indicates the charge of the cation.

Iron (II) chloride and iron (III) chloride The ion with the higher charge has a name ending

in –ic and the one with the lower charge has a name ending in –ous; ferrous chloride and ferric chloride

Naming Compounds

Ionic Compounds with Polyatomic Ions: Need to know the names of the polyatomic ions

(Table 2.5).

NH4+ ammonium, SO4

2- sulfate Na2SO4 Sodium sulfate KH2PO4 Potassium dihydrogen phosphate Fe(NO3)3 Iron(III) nitrate CsClO4 Cesium perchlorate NaOCl sodium hypochlorite Al2(Cr2O7)3 Aluminum dichromate Sr(CN)2 Strontium cyanide

Naming compoundsBinary Covalent Compounds (Type III):Formed between two nonmetalsRules: The first element in the formula is named first,

using the full element’s name Second element is name as if it were an anion Use prefixes to denote the number of atoms

present Never use mono – prefix for naming the first

element

Molecular compounds nonmetals OR nonmetals + metalloids common names

H2O, NH3, CH4, C60

element further left in periodic table is 1st

element closest to bottom of group is 1st

if more than one compound can be formed from the same elements, use prefixes to indicate number of each kind of atom

last element ends in ide

2.7

CO ==> carbon monoxide, not monocarbon monoxide

P2O5 ==> diphosphorus pentoxide

S2Cl4 ==> disulfur tetrachloride

NO2 ==> nitrogen dioxide

N2O5 ==> dinitrogen penoxide

Chemical Nomenclature Ionic Compounds

often a metal + nonmetal anion (nonmetal), add “ide” to element name

BaCl2 barium chloride

K2O potassium oxide

Mg(OH)2 magnesium hydroxide

KNO3 potassium nitrate

2.7

Transition metal ionic compounds indicate charge on metal with Roman numerals

FeCl2 2 Cl- -2 so Fe is +2 iron(II) chloride

FeCl3 3 Cl- -3 so Fe is +3 iron(III) chloride

Cr2S3 3 S-2 -6 so Cr is +3 (6/2) chromium(III) sulfide

2.7

HI hydrogen iodide

NF3 nitrogen trifluoride

SO2 sulfur dioxide

N2Cl4 dinitrogen tetrachloride

NO2 nitrogen dioxide

N2O dinitrogen monoxide

Molecular Compounds

2.7

TOXIC!

Laughing Gas

An acid can be defined as a substance that yields hydrogen ions (H+) when dissolved in water.

HCl•Pure substance, hydrogen chloride•Dissolved in water (H+ Cl-), hydrochloric acid

An oxoacid is an acid that contains hydrogen, oxygen, and another element.

HNO3 nitric acid

H2CO3 carbonic acid

H2SO4 sulfuric acid

2.7

A base can be defined as a substance that yields hydroxide ions (OH-) when dissolved in water.

NaOH sodium hydroxide

KOH potassium hydroxide

Ba(OH)2 barium hydroxide

2.7

Common Cations and Anions

Formulas from Names

Name Chemical FormulaDiphosphorus pentasulfide P2S5 (two non metals)

Cesium peroxide Cs2O2 (Cs1+, O22-)

Aluminum fluoride AlF3 (Al3+, F-1)

Vanadium (v) fluoride VF5 (V5+, F-1)

Dioxygen difluoride O2F2 (two non metals)

Gallium oxide Ga2O3 (Ga3+, O2-)

Ammonium dichromate (NH4)2Cr2O7 (NH4+, Cr2O7

2-)

Cupric phosphate Cu3(PO4)2 (Cu2+, PO43-)

Flowchart for Naming Binary Compounds

Acids

When dissolved in water produce a solution containing free H+ ions (protons)

An acid is a molecule with one or more H+ ions attached to an anion

If the anion does not contain oxygen, the acid is named with the prefix hydro – and the suffix –ic

HCl Hydrochloric acid

HCN Hydrocyanic acid

Acids If the anion contains oxygen, the acidic name is

formed from the root name of the anion with the suffix of –ic or –ous depending on the anion

HNO3 Nitric acid (Nitrate anion)

H2SO4 Sulfuric acid (Sulfate anion)

H3PO4 Phosphoric acid (Phosphate anion)

HC2H3O2 Acetic acid (Acetate anion)

H2SO3 Sulfurous acid (sulfite anion)

HNO2 Nitrous acid (nitrite anion)