CHEMISTRY 161

Chapter 3

1. Structure of an Atom

subatomic particles

electrons(‘cloud’)

protons(nucleus)

neutrons(nucleus)

m(n) / m(e) ≈ 2000 m(n) > m(p)

2. Atomic & Mass Number

AZ Xatomic number

(number of protons)

(number of electrons)

mass number

(number of protons plus neutrons)

Compounds & Chemical Reactions

1. Compounds

2. The Chemical Formula

3. The Chemical Equation

4. The Name of Chemicals

1. Compounds

molecular compounds ionic compoundsEXPI

Molecular Compounds

1. consist of electrically neutral particles called molecules

2. each molecule consists of atoms

3. atoms are connected via electrons

4. connections are called bonds(‘springs’)

EXPII

Molecular Compounds

Group Period IVA VA VIA VIIA Noble Gas 2 CH4 NH3 H2O HF Ne 3 SiH4 PH3 H2S HCl Ar 4 GeH4 AsH3 H2Se HBr Kr 5 SbH3 H2Te HI Xe

lots of molecules contain hydrogen

EXPIII

H2, He

Jupiter

PH3

CH4

EXPIV

H2, He

Saturn

NH3/PH3

CH4

H2O (s)

atom

(neutral)

add electron(s)

(reduction)

anion(Cl-)(negative charge)

(non-metal)

take electron(s)

(oxidation)

cation(Na+)(positive charge)

(metal)

Ionic Compounds I

1. consist of charged particles

2. charged particles are called ions

3. ions are formed by electron transfers from atoms

Ionic Compounds II

4. ionic compounds are held together by electrostatic forces

Cl-Na+metal non-metal

NaCl MgOEXPV

Compounds & Chemical Reactions

1. Compounds

2. The Chemical Formula

3. The Chemical Equation

4. The Name of Chemicals

2. The Chemical Formula

collection of chemical symbols used to describe the composition of

elements and compounds

NaCl

H2O Fe2O3

CaSO4 2 H2O

2. The Chemical Formula

collection of chemical symbols used to describe the composition of

elements and compounds

HeEXPVI

F F

F2 EXPVII

O2

O O

S8

N2

N N

P4

H2

H H

Compounds & Chemical Reactions

1. Compounds

2. The Chemical Formula

3. The Chemical Equation

4. The Name of Chemicals

3. The Chemical Equation

chemical equation describes what happens in a chemical reaction

chemical reaction is combination of elements and/or compounds

H2 + O2 H2O

balancing & mass conservation

2 2

3. The Chemical Equation

2 H2 + O2 2 H2O

s = solid l = liquid g = gas aq = aqueous solution

2 H2(g) + O2 (g) 2 H2O (l)

1.phosphor with oxygen

2. sulfur with oxygen

Examples

3. methane with oxygen

Compounds & Chemical Reactions

1. Compounds

2. The Chemical Formula

3. The Chemical Equation

4. The Name of Chemicals

Organic Compounds

compounds containing mostly hydrogen and carbon

minor amount other elements (N, O, S, P…)

hydrocarbons

H C

alkanes CnH2n+2

CO2

CO H2O

H2COC4H10

Organic Compounds?

C4H10 combustion

EXPVIII

Titan – Saturn’s Largest Moon

Cassini-Huygens Mission

Cassini-Huygens Mission

Inorganic Compounds

binary compounds

compounds consisting of ONLY TWO different elements

NaCl CO2 CaSO4

nomenclature naming compounds

nomen (Latin) = name

symbol stem first element second element O ox- oxygen oxide S sulf- sulfur sulfide N nitr- nitrogen nitride P phosph- phosphorus phosphide F fluor- fluorine fluoride Cl chlor- chlorine chloride Br brom- bromine bromide I iod- iodine iodide

part one (metal)

part two

English name ofelement

stem + ide

NaCl MgO BeS

Metal (Main Group) + Non-Metal

ionic compounds

(metal + non-metal)

stem + ide

Nomenclature Inorganic Compounds

main group

metal element +

ionic compounds

(metal + non-metal)

stem + ide

Nomenclature Inorganic Compounds

main group

metal element +

molecular compounds prefix + element + prefix + stem + ide

Greek Prefixes mono- = 1 (often omitted) hexa- = 6 di- = 2 hepta- = 7 tri- = 3 octa- = 8 tetra- = 4 nona- = 9 penta- = 5 deca- = 10

PF3 PF5

CO CO2

HCl

NO NO2N2O5

Molecular Compounds

ionic compounds

(metal + non-metal)

stem + ide

Nomenclature Inorganic Compounds

main group

metal

trans. group

metal

element +

molecular compounds prefix + element + prefix + stem + ide

stem + ideelement + oxstate +

FeO Fe2O3

ionic compounds

cations & anions

Mn+ Em-

metalstransition metals

nonmetals

compounds must be electrically neutral

charge state of ions

-/+3/5 -2 -1 0+1 +2 +3

-/+2/4

K2S CaCl2

main group metals – always start with cation

Chromium Cr2+, Cr3+ Zinc Zn2+ Manganese Mn2+, Mn3+ Silver Ag+ Iron Fe2+, Fe3+ Cadmium Cd2+

Cobalt Co2+, Co3+ Gold Au+, Au3+ Nickel Ni2+ Mercury Hg2

2+, Hg2+ Copper Cu+, Cu2+

NiCl2 CuO CuCl

transition metals – always start with anions

oxidation states

Mn2O3 B2O3

molecular compounds

ionic compounds

polyatomic ionic compounds

ion name ion name NH4

+ ammonium ion CO32- carbonate ion

OH- hydroxide ion H3O+ hydronium ion

NO2- nitrite ion SO3

2- sulfite ion NO3

- nitrate ion SO42- sulfate ion

ClO2- chlorite ion CrO4

2- chromate ion ClO3

- chlorate ion Cr2O72- dichromate ion

PO43- phosphate ion

ammonium chloride sodium dichromate magnesium carbonate

rubidium sulfate calcium phosphate

ionic compounds

(metal + non-metal)

stem + ide

Nomenclature Inorganic Compounds

main group

metal

trans. group

metal

element +

molecular compounds prefix + element + prefix + stem + ide

stem + ideelement + oxstate +

Mass Percentage Composition

moles of elementmoles in whole sample% mole 100%

P4O10

100% element % sample wholeof masselement of mass

= X 100 %

= X 100 %

Example

A sample was analyzed and contains 0.1417 g of nitrogen and 0.4045 g of oxygen.

Calculate the percentage composition.

1. mass of whole sample

100% element % sample wholeof masselement of mass

2. percentages of elements

= X 100 %

EMPIRICAL FORMULA

H2O

H2O2

MOLECULAR FORMULA

HO

H2O H2O

P4O10P2O5

P2*2O2*5

Example

A sample contains 0.522 g of nitrogen and 1.490 g of oxygen. Calculate its empirical formula.

N2O5

COMBUSTION

CxHy

CO2 H2O

EXPIX

COMBUSTION

C3H8 CO2 + H2O

0.013068 g

+ O2

How many grams of oxygen are consumed?

1.balance equation

2.convert to moles

The combustion of a 5.217 g sample of a compound of C, H, and O gave 7.406 g

CO2 and 4.512 g of H2O.

Calculate the empirical formula of the compound.

How many grams of Al2O3 are produced when 41.5 g Al react?

2Al(s) + Fe2O3(s) Al2O3(s) + 2 Fe(s)

Compounds & Chemical Reactions

1. Compounds

2. The Chemical Formula

3. The Chemical Equation

4. The Name of Chemicals

ionic compounds

(metal + non-metal)

stem + ide

Nomenclature Inorganic Compounds

main group

metal

trans. group

metal

element +

molecular compounds prefix + element + prefix + stem + ide

stem + ideelement + oxstate +