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Chemistry, The Central Science , 10th edition Theodore L. Brown; H. Eugene LeMay, Jr.; and Bruce E. Bursten. Chapter 2 Atoms, Molecules, and Ions. John D. Bookstaver St. Charles Community College St. Peters, MO 2006, Prentice Hall, Inc. 2. 1 The Atomic Theory of Matter. - PowerPoint PPT Presentation
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Atoms,Molecules,
and Ions
Chapter 2Atoms,
Molecules,and Ions
John D. Bookstaver
St. Charles Community College
St. Peters, MO
2006, Prentice Hall, Inc.
Chemistry, The Central Science, 10th editionTheodore L. Brown; H. Eugene LeMay, Jr.;
and Bruce E. Bursten
Atoms,Molecules,
and Ions
2. 1
The Atomic Theory of
Matter
Atoms,Molecules,
and Ions
Democritus (400 BC)• This is the Greek philosopher
Democritus• His theory: Matter could not be
divided into smaller and smaller pieces forever• eventually the smallest
possible piece would be obtained.
• This piece would be indivisible.
• He named the smallest piece of matter “atomos,” meaning “not to be cut.”
Atoms,Molecules,
and Ions
• Democritus’s theory was forgotten for over 2000 years
• The philosophers of the time, Aristotle and Plato, had a more respected, (and ultimately wrong) theory.
• Aristotle and Plato favored the earth, fire, air and water approach to the nature of matter.
Atoms,Molecules,
and Ions
Atomic Theory of Matter
• The theory that atoms are the fundamental building blocks of matter reemerged in the early 19th century, championed by John Dalton.
Known as the “Father of the Atom”
First scientist to support the existence of the atom with scientific evidence
Atoms,Molecules,
and Ions
Dalton’s Postulates1) Elements are made up of atoms
2) Atoms of each element are identical (in mass and properties). Atoms of different elements are different.
3) Chemical reactions are a rearrangement of atoms. Atoms are not created or destroyed.
4) Compounds are formed when atoms of multiple elements combine. Each compound has specific numbers and kinds of atoms.
Atoms,Molecules,
and Ions
Dalton’s Atomic Theory• He deduced that all
elements are composed of atoms. Atoms are indivisible and indestructible particles.
• Atoms of the same element are exactly alike.
• Atoms of different elements are different.
• Compounds are formed by the joining of atoms of two or more elements.
Atoms,Molecules,
and Ions
Law of Constant Composition
• From Dalton’s 4th postulate• Also known as the law of definite
proportions.• The elemental composition of a pure
substance never varies. In a compound or element, the numbers
and kinds of atoms are constant.
Atoms,Molecules,
and Ions
Law of Multiple Proportions• When chemical elements combine, they do so in a ratio of
small whole numbers. For example, carbon and oxygen react to form carbon
monoxide (CO) or carbon dioxide (CO2), but not CO1.3.
• Further, if two elements, A & B, combine to form more than one compound, the masses of B that combine with a given mass A are in the ratio of small whole numbers
• Example:
Water H2O vs Hydrogen Peroxide H2O2
Mass O = 16 g Mass O = 32 g
Mass H = 2 g Mass H = 2 g
Oxygen 32 g : 16 g = 2
Hydrogen 2 g : 2 g = 1
Atoms,Molecules,
and Ions
Law of Conservation of Mass
• From Dalton’s 3rd postulate• The total mass of substances present at
the end of a chemical reaction is the same as the mass of substances present before the reaction took place.
Atoms,Molecules,
and Ions
2. 2
Discovery of Atomic
Structure
Atoms,Molecules,
and Ions
J.J. Thompson’s Experiment• Using a cathode ray tube Thompson
found that passing an electric current makes a beam of radiation appear to move from the negative to the positive end
• By adding an electric field to the cathode ray tube, he found that the beam deflected towards the positive field so he deduces that the components of the beam were negative
Atoms,Molecules,
and Ions
Cathode Rays & Electrons• Radiation was passed through a tube from
the cathode (negative end) to the anode (positive end) The radiation would fluoresce (give off light) When an electric/magnetic field was applied, the
cathode rays deflected in a manner consistent with a stream of negative particles
Since the gas was known to be neutral (having no charge) he reasoned that there must also be positively charged particles in the atom (but he could never find them).
(Old TV sets were cathode ray tubes)
Atoms,Molecules,
and Ions
The Electron
• Streams of negatively charged particles were found to emanate from cathode tubes.
• J. J. Thompson is credited with their discovery (1897).
• Thompson measured the charge/mass ratio of the electron to be 1.76 108 coulombs/g.
Cathode Ray
Atoms,Molecules,
and Ions
• Robert Millikan put a charge onto a tiny drop of oil and dropped it into an electric field
• When the field was manipulated, the oil drop’s free fall was affected
• By measuring how strong an applied electric field had to be in order to stop the oil drop in mid air, he was able to work out the mass of the drop
• He could calculate the force of gravity on one drop and thus the electric charge that the drop must have.
• By varying the charge on different drops, he noticed that the charge was always a multiple of -1.6 x 10-19 C, the charge on a single electron
Millikan’s Oil Drop Experiment
Atoms,Molecules,
and Ions
Millikan’s Oil Drop Experiment
• Once the charge/mass ratio of the electron was known, determination of either the charge or the mass of an electron would yield the other.
Millikan’sOil Drop Experiment
Atoms,Molecules,
and Ions
Radioactivity:
• The spontaneous emission of radiation by an atom.
• First observed by Henri Becquerel.• Also studied by Marie and Pierre Curie.
Atoms,Molecules,
and Ions
Radioactivity• Three types of radiation were discovered by
Ernest Rutherford: [alpha] particles (positive charge) [beta] particles are high speed e– (neg. charge) [gamma] rays are unaffected by electric field/charge
Atoms,Molecules,
and Ions
“Plum Pudding” Model• In 1897, the English scientist J.J.
Thompson provided the first hint that an atom is made of even smaller particles.
• Thompson concluded that the negative charges came from within the atom.
• A particle smaller than an atom had to exist… the atom was divisible!
• Positive sphere of matter with negative electrons imbedded in it
Atoms,Molecules,
and Ions
Rutherford’s Gold Foil Experiment• 1909 - Ernest Rutherford shot [alpha] particles at
a thin sheet of gold foil and observed the pattern of scatter of the particles.
Gold Foil Experiment
Atoms,Molecules,
and Ions
• Top: Expected results: alpha particles (+) should pass through the plum pudding model of the atom undisturbed.
• Bottom: Observed results: Some of the particles were deflected at large angles, indicating a small, concentrated positive charge.
Results of the Gold Foil Experiment
Atoms,Molecules,
and Ions
The Nuclear Atom
• Rutherford predicted that most of the volume of the Au atoms was open, empty space. The “plum pudding” model could not be correct.
• Rutherford concluded that an atom must have a small, dense, positively charged center (the nucleus) that repelled his positive particles
• He also concluded that the e– were outside of the nucleus
Atoms,Molecules,
and Ions
Other Subatomic Particles
• Protons discovered by Rutherford in 1919.
• Neutrons discovered by James Chadwick in 1932.
Atoms,Molecules,
and Ions
2. 3
The Modern View of Atomic
Structure
Atoms,Molecules,
and Ions
Subatomic Particles
• Protons and electrons the only particles that have a charge.
• Protons and neutrons have essentially the same mass.
• The mass of an electron is so small that we ignore it (p+ and no are 1800x mass of e–).
Atoms,Molecules,
and Ions
Inside the Atom• Protons and neutrons reside inside the nucleus of
the atomThough the nucleus is extremely small, it
contains nearly all the mass of the atom
http://ed.ted.com/lessons/just-how-small-is-an-atom
Atoms,Molecules,
and Ions
Atomic Mass & Size• Because atoms have such tiny masses (heaviest
is 4.0 x 10-22 g) we use the atomic mass unit (amu)1 amu = 1.66 x10-24 g
• Atoms are very small so another common unit of length used is the Angstrom (Å) diameters between 1x10-10 m and 5x10-10 m
= 100-500 pm
= 1 – 5 Å
Atoms,Molecules,
and Ions
Atomic Numbers, Mass Numbers, and Isotopes
Atoms,Molecules,
and Ions
Atomic Number (Z)
• the # of protons an atom contains
• is unique to each element
• Thus, # of p+ tells the identity of the atom
• Because atoms are neutral, every atom has an equal number of protons and electrons
Atoms,Molecules,
and Ions
Mass Number (A)
• Mass # = protons + neutrons
• Mass of atoms in amu
• Atoms of an element can differ in the # of neutrons they containAs a result, atoms of the same element
can have different masses
Atoms,Molecules,
and Ions
Practice Counting p+, no, and e–
• p+ and e– = 15• no = 31-15 = 16
• p+ and e– = 26• no = 56 -26 = 30
• p+ and e– = 10• no = 20-10 = 10
Atoms,Molecules,
and Ions
Isotopes:
• Atoms of the same element (thus same # protons) with different masses and different #s of neutrons.
116C
126C
136C
146C
• Hyphenated notation:Carbon -12, Carbon -14, etc
• Standard notation:
Atoms,Molecules,
and Ions
More Practice• How many protons, neutrons, and electrons
are in the following?
1)108Ag
2)Nickel-60
3)209Pb
4)Silicon-30
p+ = 47; no = 108-47 = 61; e– = 47
p+ = 28; no = 60-28 = 32; e– = 28
p+ = 82; no = 209-82 = 127; e– = 82
p+ = 14; no = 30-14 = 16; e– = 14
Atoms,Molecules,
and Ions
2. 4
Atomic Weights
Atoms,Molecules,
and Ions
24Cr
51.996
Atomic Mass
• Carbon-12 is the standard for atomic masses of elements:• It was assigned an exact mass of 12.00 amu• All other atomic masses were determined in
comparison to the mass of Carbon-12
• The periodic table gives the masses of an “average” atom of each element must be an avg. because there are multiple
isotopes of each element present in natureknown as the average atomic mass
Atoms,Molecules,
and Ions
Average Atomic Mass
• Avg. atomic mass is determined by mass of each isotope AND each isotope’s relative abundance (how much
of that isotope is found in nature)That means that it is a weighted average of all
the naturally occurring isotopes of that element.Thus, avg. atomic mass is not a whole #
• Time for some math! *Notes Handout – Weighted Average*
Atoms,Molecules,
and Ions
Weighted Average Example• On the first day of school, Maggie’s Geometry teacher
told the class that all grades would be calculated by the weighted average system seen below:Participation: 15% Homework: 20%
Quizzes: 25% Tests: 40% • At the end of the MP1, Maggie’s not sure if she is
passing the class. She needs to know what her overall weigthed class average is. Below are Maggie’s average grades during MP1. Let’s help her! Maggie’s MP1 Averages
Participation: 70 Homework: 74
Quizzes: 72 Tests: 66
Atoms,Molecules,
and Ions
Avg. Atomic Mass Calculations
Avg. atomic mass (AAM) =
[(rel, abundance isotope A) x (mass isotope A)]
+ [(rel. abundance isotope B) x (mass isotope B)]
+ [(rel. abundance isotope C) x (mass isotope C)]
…etc
*** Relative Abundance = % abundance ***
100
- application of a weighted average -
Atoms,Molecules,
and Ions
Avg. Atomic Mass Practice• Magnesium has three naturally occurring isotopes:
78.70% of Mg exists as Magnesium-24 (23.985 amu),
10.03% exist as Magnesium-25 (24.986 amu) and
11.17% exist as Magnesium-26 (25.983 amu). What is the average atomic mass of Magnesium?
• Avg. atomic mass Mg=
= 18.876 amu
+ 2.506 amu
+ 2.902 amu
= 24.284 amu
+ (0.1003)(24.986 amu) + (0.1117)(25.983 amu)
(0.7870)(23.985 amu)
Atoms,Molecules,
and Ions
2. 5
The Periodic Table
Atoms,Molecules,
and Ions
The Periodic Table of Elements
Atoms,Molecules,
and Ions
Periodic Table
• Period/Series = horizontal rows (#1-7, lanthanides, actinides)
• Families/Groups = vertical columns(#1-18, special names for some)Elements in the same
family have similar chemical and physical properties.
Atoms,Molecules,
and Ions
Periodicity & Periodic Law
Looking at the elements in the periodic table, there is a reoccurring pattern of chemical and physical properties at intervals.
Atoms,Molecules,
and Ions
Periodic Table
Nonmetals are on the right side of the periodic table (with the exception of H).
Atoms,Molecules,
and Ions
Periodic Table
Metalloids border the staircase line.
Atoms,Molecules,
and Ions
Periodic Table
Metals are on the left side of the chart.
Atoms,Molecules,
and Ions
1A – Alkali Metals(form +1 charge)
Atoms,Molecules,
and Ions
2A – Alkali Earth Metals(form +2 charge)
Atoms,Molecules,
and Ions
1B – Coinage Metals
Atoms,Molecules,
and Ions
6A – Chalcogens(form –2 charge)
Atoms,Molecules,
and Ions
7A – Halogens(form –1 charge)
Atoms,Molecules,
and Ions
8A – Noble Gases (unreactive & very stable)
Atoms,Molecules,
and Ions
Lanthanide Series
Atoms,Molecules,
and Ions
Actinide Series(radioactive; many man-made)
Atoms,Molecules,
and Ions
2. 6
Molecules & Molecular
Compounds
Atoms,Molecules,
and Ions
Chemical Formulas
• The subscript to the right of an elemental symbol tells the number of atoms of that element present in one molecule of the compound.Ex: NH4 = 1 nitrogen atom
& 4 hydrogen atoms
Atoms,Molecules,
and Ions
Molecular Compounds• Compounds which are
composed of molecules, contain more than 1 type of atom, and are almost always composed of only nonmetalsEx: Figure 2.20 (left)
• The composition of each compound is given by its chemical formula
Atoms,Molecules,
and Ions
Diatomic Molecules• Many elements in nature are found most
commonly in their molecular form Diatomics are two of the same atom bound togetherONLY the elements: Br2-I2-N2-Cl2-H2-O2-F2
When we speak of hydrogen, it is automatically H2 unless specified otherwise (same for other diatomics)
Atoms,Molecules,
and Ions
Types of Formulas
• Molecular formulas give the exact number of atoms of each element in a compound.Ex: H2O2 or C4H10
• Empirical formulas give the lowest whole-number ratio of atoms of each element in a compound.Ex: HO or C2H5
Atoms,Molecules,
and Ions
Picturing Atoms• Chemical formulas only
show what elements are present in an atom, not how they are bonded togetherCH4
• Structural formulas show the order in which atoms are bonded. .
Atoms,Molecules,
and Ions
Molecular or Empirical Formulas?
C6H6
C8H18
WO2
C3H6O2
X39Y13
Molecular
Molecular
Empirical
Empirical
Molecular
Atoms,Molecules,
and Ions
2. 7 Ions & Ionic Compounds
Atoms,Molecules,
and Ions
Ions
• When atoms lose or gain electrons, they become ions.Cations are positively chargedAnions are negatively charged
+Cations
–Anions
Atoms,Molecules,
and Ions
Ions• The nucleus of an atom is left unchanged by
a chemical rxn, but atoms will readily loose or gain e–
Gaining e– creates negative anionsLosing e– creates positive cations
Atoms,Molecules,
and Ions
Atoms to Ions…
• The ion has a –1 charge because it has one more electron than its number of protons (18 e– vs.17 p+)
Atoms,Molecules,
and Ions
Counting Subatomic Particles in Ions
How many p+ and e– are in Se2– ?
• # Protons ALWAYS = atomic #… 34 p+
• # Electrons depends on IONIC CHARGE2– charge means two more electrons than
protons (Se atom gained two e–) ... 34 p+ + 2 = 36 e–
Atoms,Molecules,
and Ions
Counting Subatomic Particles in Ions
How many p+ and e– are in K+ ?
• # Protons ALWAYS = atomic #… 19 p+
• # Electrons depends on ionic charge+1 charge means one less electron than
protons (K atom lost one e–) ... 19 p+ - 1 = 18 e–
Atoms,Molecules,
and Ions
Practice with Monatomic Ions
# Protons
7
35
38
3
16
Ions
N3-
Br -
Sr2+
Li+
S2-
# Electrons
10
36
36
2
18
Atoms,Molecules,
and Ions
Polyatomic Ions
• Ions which have two or more different atoms joined as a molecule
will have a net negative or positive charge.
Ex: NO3– = nitrate ion
SO42 – = sulfate ion
Atoms,Molecules,
and Ions
Predicting Ionic Charges• The goal of any atom is...
To gain/lose e– so that it will have the same # of e– as the noble gas nearest to it
All atoms want to have stable arrangements like the Nobel gases!
Atoms,Molecules,
and Ions
Predicting Ionic Charges- using the periodic table to predict charges -
Atoms,Molecules,
and Ions
Common Cations
Atoms,Molecules,
and Ions
Common Anions
Atoms,Molecules,
and Ions
Ionic Bonds• Transfer of electrons from one substance to
another• Ionic compounds (such as NaCl) are generally
formed between metals and nonmetals.Ex: Neutral Na atom + Neutral Cl atom …
Na gives e– to Cl Na+ and Cl–
Because opposite charges attract, Na+ and Cl– bind together to form a neutral ionic compound, NaCl.
Atoms,Molecules,
and Ions
Practice - Ionic vs. Molecular• Which of the following are ionic compound and
which are molecular compounds?
N2O
Na2O
CaCl2
SF4
CrCl2
nm + nm = molecular
m + nm = ionic
ionic
molecular
ionic
Atoms,Molecules,
and Ions
Ionic Compounds
• Ionic Compound cation + anion metal + nonmetalNeutral compound (no net charge)
• Total + charge and – charge MUST be equal in order to cancel with each other
Atoms,Molecules,
and Ions
Criss-Cross Method• Method for writing empirical ionic formulas
Step 1: Write the cation down first, followed by the anion right next to it
Step 2: The charge of the cation becomes the subscript of the anion
Step 3: The charge of the anion becomes the subscript of the cation
Step 4: If the subscripts are not in the lowest whole-number ratio, divide by the greatest common factor (because ionic compounds will only have empirical formulas)
Atoms,Molecules,
and Ions
Criss-Cross Method Example• Write the empirical formula for the
compounds formed by the following ions: Mg2+ and N3–
Atoms,Molecules,
and Ions
Formulas w/Polyatomics
• Ionic bonds also form with polyatomic ions• Treat the polyatomic as a single particle• After the criss-cross technique, if the subscript
for the entire polyatomic ion is 2 or more, surround the the polyatomic ion in parenthesesEx: Ammonium Sulfide
NH4+ and S2–
(NH4)2S
• Do not change the subscripts of the polyatomic ion itself!!!
Atoms,Molecules,
and Ions
Criss-Cross Method Practice• Write the empirical formula for the
compounds formed by the following ions:
1) Na+ and PO43–
2) Zn2+ and SO42–
3) Fe3+ and O2–
4) Al3+ and CO32–
Na3PO4
ZnSO4
Fe2O3
Al2(CO3)3
Atoms,Molecules,
and Ions
2. 8
Naming Inorganic
Compounds
Atoms,Molecules,
and Ions
Chemical Nomenclature
• Organic CompoundsContain the elements C, O, H, N, SHave their own naming system
• Inorganic CompoundsIonic CompoundsMolecular CompoundsAcids
Atoms,Molecules,
and Ions
Naming Ionic Compounds
Atoms,Molecules,
and Ions
Naming Ionic Cations
• Monatomic cations from metal atoms
have the same name as the metal
• Na+ sodium ion • Zn2+ zinc ion
The following only form only cation:
• group 1A, 2A, Al3+, Ag+, Zn2+
Atoms,Molecules,
and Ions
Naming Ionic Cations• Cations from transition metals
Transition metals can form different cations charge is indicated by a roman numeral in
parentheses after the name of the metal
• Fe2+ iron (II) ion • Fe3+ iron (III) ion
Older naming system – also distinguishes differently charged ions:
• Fe2+ Ferrous (lower charge)• Fe3+ Ferric (higher charge)
Atoms,Molecules,
and Ions
Naming Ionic Anions
• Monatomic anions formed from nonmetals
named by replacing the ending with the suffix –ide
• O2– oxide ion• N3– nitride ion• S2– sulfide ion• some polyatomics end in –ide (OH–, CN–)
Atoms,Molecules,
and Ions
Naming Ionic Anions
• Polyatomic anions containing oxygen (aka: oxyanions) either end in: –ite (lower # oxygen) or –ate (higher # oxygen)
• SO32– sulfite ion • NO2
2- nitrite ion
• SO42– sulfate ion • NO3
2- nitrate ion
• Prefixes for extended oxyanions:
• ClO– hypochlorite ion (fewest oxygens)
• ClO2– chlorite ion (2nd fewest oxygens)
• ClO3– chlorate ion (2nd most oxygens)
• ClO4– perchlorate ion (most oxygens)
Atoms,Molecules,
and Ions
Inorganic Nomenclature - Basics
• Write the name of the cation.• If the cation can have more than one
possible charge (transition metals), write the charge as a roman numeral in parentheses.
• If the anion is an element, change its ending to -ide; if the anion is a polyatomic ion, simply write the name of the polyatomic ion.
Atoms,Molecules,
and Ions
Practice Naming Ionic Compounds
Examples:
NH4OH
• NH4+ + OH–
• ammonium hydroxide
CuI2
• Cu2+ + I–
• Copper (II) Iodide• Cupric Iodide
LiCl• Li+ + Cl– • lithium chloride
MgS• Mg2+ + S2–
• Magnesium sulfide
Atoms,Molecules,
and Ions
Practice Writing Ionic FormulasExamples:
calcium carbonate • Ca2+ + CO3
2–
• CaCO3
ammonium nitrate • NH4
+ + NO3–
• NH4NO3
magnesium hydroxide • Na2+ + OH– • Mg(OH)2
iron (III) carbonateferric carbonate
• Fe3+ + CO32–
• Fe2(CO3)3
Atoms,Molecules,
and Ions
Naming Acids
Atoms,Molecules,
and Ions
Some Acid Basics…• Hydrogen (H+) containing compounds
• For now, the formula of an acid will have hydrogen listed as the first element
• Consider an acid to be composed of an anion connected to enough H+ ions to balance the anion's charge
• Examples of acids:HCl H+ and Cl– H2SO4 2H+ and SO4
2–
Atoms,Molecules,
and Ions
Acid Nomenclature• If the anion in the acid ends in -ide, change the
ending to -ic acid and add the prefix hydro- :
HCl:• H+ and Cl– (chloride ion)• hydrochloric acid
HBr:• hydrobromic acid
HI: • hydroiodic acid
Atoms,Molecules,
and Ions
Acid Nomenclature
• If the anion in the acid ends in -ite, change the ending to -ous acid:
HClO• H+ and hypochlorite• hypochlorous acid
HClO2
• H+ and chlorite• chlorous acid
ite/ous=
Lower
Atoms,Molecules,
and Ions
Acid Nomenclature• If the anion in the acid ends in -ate, change the
ending to -ic acid:
HClO3
• H+ and chlorate• chloric acid
HClO4
• H+ and perchlorate• perchloric acid
H2SO4
• H+ and sulphate• sulfuric acid
ate/ic=
Higher
Atoms,Molecules,
and Ions
Atoms,Molecules,
and Ions
Naming Binary Molecular
Compounds
[aka: Covalent Compounds]
Atoms,Molecules,
and Ions
Binary Molecular Compounds• Nonmetal + nonmetal
• The element farther to the left in the periodic table (the less electronegative atom) is usually listed first.
• A prefix is used to denote the number of atoms of each element in the compound
• The prefix mono- is never used on the first element listed, however.)
Atoms,Molecules,
and Ions
Binary Molecular Compounds
• The ending on the more electronegative element (furthest to the right in periodic table) is changed to -ide.
CO2
• carbon dioxide
CCl4 • carbon tetrachloride
Atoms,Molecules,
and Ions
Binary Molecular Compounds
• If the prefix ends with a or o and the name of the element begins with a vowel, the two successive vowels are often merged into one:
• N2O5
dinitrogen pentoxide
Atoms,Molecules,
and Ions
Practice Naming Binary Molecular Compounds
Examples:
Cl2O
• dichlorine monoxide
NF3
• nitrogen trifluoride
N2O4
• dinitrogen tetroxide
P4S10
• tetraphosphorous decasulfide
Atoms,Molecules,
and Ions
Practice Writing Molecular Formulas
Examples:
phosphourous triiodide • PI3
diborane trioxide• B2O3
dihygrogen monoxide • H2O
iodine monobromide• IBr
Atoms,Molecules,
and Ions
2. 9
Simple Organic
Compounds
Atoms,Molecules,
and Ions
Organic Compounds• Studies compounds which contain carbon
• Typically, organic compounds have carbon bonded with H, O, S, and P
• Hydrocarbonscontain only C and H In the simplest group, alkanes, each carbon is
bonded to four other atomsAlthough they are binary molecular compounds,
they are NOT named like the inorganics in section 2.8.
Atoms,Molecules,
and Ions
Facts about Naming Organic Compounds
• For alkanes, the ending of the compound will always be -ane
• Distinct organic prefixes are used to tell you the # of C atoms in the compoundExample prefixes:
• meth = 1• eth = 2• Prop = 3 etc…
Atoms,Molecules,
and Ions
Alkanes
• These are the 3 simplest alkanes containing 1, 2 and 3 carbon atoms
Atoms,Molecules,
and Ions
Derivatives of Alkanes• Other organic compounds form when some of the H in
an alkane are replaced with functional groups.There are several different functional groupsEx: an alcohol is an alkane which had hydrogen replaced
with OH (not an ion so NOT the polyatomic hydroxide)
Recommended