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Transcript of Instructor: Liu Dapeng ( Department of Chemistry, College of Science ) E-mail: [email protected]...
Instructor: Liu Dapeng ( Department of Chemistry, College of Science )
E-mail: [email protected] Plan
Chapter 1: Introduction Chapter 2: Measurement
Chapter 3: Stoichiometry Chapter 4: Reactions in Solution
Chapter 5: Gases Chapter 6: Thermochemistry
Chapter 7: Atomic structure Chapter 8: Periodic Table
Chapter 9: Chemical Bonds
Chapter 14: Chemical Equilibrium
Chapter 15: Acids and Bases
Chapter 17: Chemical Thermodynamics
1.7 Teaching Arrangement
Ch1-Ch9, Ch14-15 , Ch17
Two main topics:
Basic laws and principles of chemical reactions and their applications in different systems, (macroscopical)
Atomic structure and structure of substance. (microscopical)
1. Content
2. Ways to learn and Requirements
Preparation
Attendance of the lecture and necessary notes
Review and homework
Experiments in lab
Question- answering
All-around review and examination
Learning skills:
(1) Listen to the teacher carefully and take notes when necessary. (The teacher repeated: important? Can not understand in class?)
(2) Read the textbook and find out problems. (Refer to related books? Search online? Discuss with classmates? Discuss with the teacher?)
(3) Finish the assignments by yourself.
(4) Summarize each chapter. (Understand the theory. Know the general procedure of solving problems. Remember the important parts. )
Make progress everyday!
3. Evaluation and score
The final score = Attendence×10% + Homework×10%
+ Experiment operation and report×10% +
Examination×70%
Your final score depends on your own performance!
1 Introduction Contents
1-1 The Scope of Chemistry
1-2 Properties of Matter: Physical and Chemical properties
1-3 Classification of Matter:
Elements, Compounds and Mixtures
1-4 The Scientific Method
1-5 Atoms
1-6 Naming Inorganic Compounds
1-7 Teaching Arrangement
1-1 The Scope of Chemistry
• Chemistry is the science that is concerned with the
composition, structure, and properties of matter and the changes
that matter undergoes.
• Matter is anything that occupies apace. Matter is made up of
almost infinitesimally small building blocks called atoms.
• Atoms can combine together to form molecules.
Molecules of a few familiar substances are represented here.
Chemistry
Inorganic Chemistry
AnalyticalChemistry
Physical Chemistry
Organic
Chemistry
• Chemistry is the science that is concerned with the composi
tion, structure, and properties of matter and changes that matte
r undergoes. Generally chemistry mainly includes four branches,
they are:
The Classification of Chemistry:
• Inorganic Chemistry (initial chemistry)
The study of the synthesis and behavior of inorganic and organometallic compounds. It has appli
cations in every aspect of the chemical industry including:
Catalysis
Material Science
Solid State Chemistry
Semiconductor
Petroleum Industry
Analytical Chemistry (measurement chemistry)
The science of obtaining, processing, and communicating inform
ation about the composition and structure of matter. It is the art
and science of determining what the matter is and how much of i
t exists.
Environmental Chemistry
Pharmaceutical Analysis
Chemical Analysis
It can detect the quality of the oil and get much information
about oil in three minutes. It is very light, portable and convenient
for analyzing the oil that is being used in all kinds of fields. It can
also be used to analyze the quality of water and other materials if
you have the appropriate software.
oil quality analyzer 2 oil quality analyzer I
Real-Space Identification of Intermolecular Bonding with
Atomic Force Microscopy
AFM measurements of 8-hq assembled clusters on Cu(111).
8-hq
• Organic Chemistry (synthesis mechanism)
The branch of chemistry that deals with the structure, propertie
s, and reactions of compounds that contain carbon.
Pharmaceutical Chemistry
Biochemistry
Polymer
Synthesis Chemistry
• In 19C, Liebig analyzed a lot of organic compounds.
• In 1824, Wöhler synthesized urea successfully.
• In 1865, KeKule proposed the ring structure of benzene.
Physical Chemistry (based theory)
•to develop a fundamental understanding at the molecular and at
omic level of how materials behave and how chemical reactions
occur. With the knowledge that is relevant in nearly every area of
chemistry, it has diverse topics:
Material Science
Fundamental Chemistry
Quantum computers
Petroleum Industry
G. N. Lewis (1875-1946)
Gilbert Newton Lewis was an
American physical chemist known for
(1) the discovery of the covalent bond
(2) purification of heavy water
(3) reformulation of chemical
thermodynamics in a mathematically
rigorous manner accessible to ordinary
chemists
(4) his theory of Lewis acids and bases
(5) his photochemical experiments
(6) coined the term “photon" for the smallest
unit of radiant energy.
G. N. Lewis have responded: Physical chemistry is everything that is interesting!
Scope of Chemistry
new materials, energy, health and environment.
food, clothing, housing and transportation -- the four basic needs of everybody.
agriculture, industry, national defense and science and technology.
Society requires improved methods of pollution control;
substitutes for scarce materials;
nonhazardous means of disposing of toxic wasters;
and more efficient ways to extract energy from fuels.
Chemists work in all
these areas.
Chemists must design strategies to extract or synthesize all kinds of things from relatively simple stating material;
Definition
Chemistrydefinition The scientific discipline that treats
the composition, properties, and transformations of matter.
Matterdefinition Anything that occupies space and
has mass; the physical material of the universe.
Atom:definition
The smallest representative particle of an element.
Moleculedefinition
A chemical combination of two or more atoms.
• Chemistry is the study of the properties of materials
and the changes that materials undergo.
• Chemistry is central to our understanding of other
sciences.
• Chemistry is also encountered in everyday life.
Why Study Chemistry
Graphene
The SEM images graphene The Raman images graphene
Graphene has been studied and applied widely all over the world for its unique properties such as the thinnest and hardest nanomaterial, almost completely transparent, very high thermal conductivity and electron mobility higher than that of carbon nano-tube or silicon crystal, the world's minimum resistivity.
The ideal crystalline structure of graphene is a hexagonal grid
Graphene
Challenges to 21 Century
• Global warming and environmental protection
• Development of new energy sources • Development of nano-technology
• Development of life science
Chemistry is the central science today!
Nanotech in sustainable energy application
solar panels nanocatalysts in petroleum treating
1-2 Properties of Matter
Properties of matter
physical properties
chemical properties
Hardness, color, melting point and density
sodium and potassium react
with water
Properties of matter can be divided into physical properties and chemical properties.
Properties of matter
intensive properties
extensive properties
such as mass and volume: depend on sample size
Properties of matter also can be divided into
intensive properties and extensive properties.
such as density, color, and
boiling point
Physical and Chemical properties
Properties that do not involve substances changing into other substances are called physical properties, which are those that we can determine without changing the identity of the substance we are studying.
The physical properties of sodium metal is: it is a soft, lustrous, silver-colored metal with a relatively low melting point and low density.
For instance
Figure 1.1 shows a chunk of metallic sodium.
These properties, then, must be determined using a process
that changes the identity of the substance of interest. To
determine, we would have to combine an alkali metal with water
and observe what happens.
2Na(s) + 2H2O(l) 2NaOH(aq) + H2(g)
Properties that involve substances changing into other
substances are called chemical properties, which describe the
way a substance can change or react to form other substances.
For exampleOne chemical property of sodium and potassium is that they can react with water:
•A change that doesn’t involve changing any substance into any other substance is called a physical change. In a chemical change, one or more substances are changed into other substances.The changes undergone by sodium and potassium when they react with water are chemical changes. Matter can also undergo physical changes. One example is the melting of a solid.
Physical and Chemical changes
changes of matter
Physicalchanges
Chemical changes
All changes of state are physical changes
Changes of matter’s
chemical identity
Figure 1.2 Three States of the matter
1. A freshly cut surface of sodium quickly
becomes dull with a film of white sodium
oxide when it is exposed to air. Is this a
physical change or a chemical change?
Physical or Chemical
Questions
choice
2. Another property of sodium is that it conducts
electricity, as do all metals. Is electrical
conductivity an intensive or extensive
property of sodium metal?
Intensive or Extensive
Questions
choice
1.3 Classification of matter by composition
• Elements consist of a unique type of atom.
• Molecules can consist of more than one type of element.
– Molecules that have only one type of atom (an element).
– Molecules that have more than one type of atom (a compound).
• If more than one atom, element, or compound are found together, then the substance is a mixture.
Pure Substances and Mixtures
Compounds
• Most elements interact to form compounds.
• Example, H2O
• The proportions of elements in compounds are the s
ame irrespective of how the compound was formed.
• Law of Constant Composition (or Law of Definite P
roportions):
–The composition of a pure compound is always the
same.
• Pure Substances and Mixtures
• Pure Substances and Mixtures
• If matter is not uniform throughout, then it is a heterogeneous mixture.
• If matter is uniform throughout, it is homogeneous.
• If homogeneous matter can be separated by physical means, then the matter is a mixture.
• If homogeneous matter cannot be separated by physical means, then the matter is a pure substance.
• If a pure substance can be decomposed into something else, then the substance is a compound.
Definition
Substancedefinition
combinations of two or more substances in which each substance retains its chemical identity. Have varying compositions and can be separated by physical changes.
Compoundsdefinition substances composed of two or
more elements; they contain two or more kinds of atoms .
Elementsdefinition substances that cannot be
decomposed into simpler substances. On the molecular level, each element is composed of only one kind of atom.
Mixturesdefinition
matter that has distinct properties and a composition that does not vary from sample to sample.
Definition
Homogeneous
definition Have only one phase. Mixtures that are uniform throughout are homogeneous. Homogeneous mixtures are also called solutions
Phasedefinition A sample of matter that is uniform
in composition and physical state and is separated from other phases by definite boundaries.
Heterogeneousdefinition
Do not have the same properties throughout the sample.
1. Iced tea2. Isopropyl alcohol3. Helium4. Sugar
Questions
Each of the following can be classified as a heterogeneous mixture, pure substance, compound, or element. How would you classify each?
1. Iced tea: heterogeneous mixture
2. Isopropyl alcohol: pure substance
3. Helium: pure substance and element
4. Sugar: pure substance and compound
Answers:
Matter can be classified according to its composition.
All matter
Can it be separated by physical method?
No Yes
Substance Mixture
Can it be decomposed by
chemical process?
Is it uniform throughout?
Compound Element HomogenousHeterogeneous
NoYes No Yes
Separate
A heterogeneous mixture
the components of ink
by filtration
using chromatography
a homogeneous mixture
by distillation
Methods of Separating Mixtures
A mixture can be separated into its components by appropriate physical means. For example: we can
• Chromatography can be used to separate mixtures
that have different abilities to adhere to solid
surfaces.
• The greater the affinity the component has for the
surface (paper) the slower it moves.
• The greater affinity the component has for the liquid,
the faster it moves.
• Chromatography can be used to separate the
different colors of inks in a pen.
States of Matter
• Matter can be a gas, a liquid, or a solid.
• These are the three states of matter.
• Gases take the shape and volume of their container.
• Gases can be compressed to form liquids.
• Liquids take the shape of their container, but they do have their own volume.
• Solids are rigid and have a definite shape and volume.
Figure 1.3 Filtration separates a liquid from a
solid.
A mixture of solid and liquid
can be separated by
filtration through a funnel
and filter paper, which is
physical means.
Filtratioin
Figure 1.4 The solution is boiled and steam is driven off.
Saltwater is a
homogeneous mixture
and a solution.
Saltwater can be
heated until the water
changes into steam
and then cooled until it
becomes water again.
This is the process of
distillation.
Distillation
Figure 1.5 Salt remains after all water is boiled off.
Salt remains and the
water is vaporized and
cooled again. The
principles of the
method is utilizing the
different boiling
points of the different
components of the
mixture.
Distillation
Figure 1.6 No chemical change occurs when salt water is distilled.
Distillation is the physical change.
Figure 1.7 Separation of a sand-saltwater mixture.
Union of Filtration and Distillation
The substances produced by the electrolysis of water cannot be further separated by any physical or chemical means. Water is 11 percent hydrogen and 89 percent oxygen by mass. This is an example of the law of constant composition.
Decomposing water
Each, can be decomposed into other substances by a chemical process. For example, the water can be decomposed into oxygen and hydrogen , namely electrolysis.
2H2O(g) O2(g) + 2H2(g)
For Exampl
e
11 percent
89 percent
Electrolysis, the
decomposition of water
by an electric current, is
a chemical process.
Figure 1.8 Electrolysis of H2O
1-4 The Scientific Method
Observation: natural or experimental
Tentative explanation: hypothesis
Revise if experiments show hypothesis is inadequate
Experiments designed to test hypothesis
Theory(or model) that amplifies hypothesis and gives predictions
Modify theory if experiments show model is inadequate
Experiments to test predictions of theory
Theory established unless later experiments or observations show inadequacies of model
However, it is wrong to suppose that merely following a set of procedures, rather like using a cookbook, will guarantee scientific success.
The Scientific method
observation experimentation
hypothesestheories
The Scientific method is the combination of.
Definition
Natural lawdefinition concise statements, often in
mathematical form, of the facts of nature.
Theorydefinition A model or way of looking at nature
that can be used to explain natural laws and make further predictions about natural phenomena.
hypothesisdefinition
A hypothesis is a tentative explanation of a natural law.
1-5 Atoms
• Matter is made up of very small particles called atoms.
• The modern atomic theory was suggested by an English
schoolteacher, John Dalton, in 1803-07:
1. All matter is composed of atoms. Atoms is the smallest
particles of an element that takes part in chemical reactions.
2. All atoms of a given element are alike. Atoms of different
elements are different.
3. Compounds are combinations of atoms of more than one
element; in a given compound, the relative number of each
type of atom is always the same.
4. Atoms cannot be created or destroyed.
• Nucleus: is at the center of the atom and is
small, dense, and positively charged.
Proton: Small particles with a unit of positive charge
in the nucleus of a atom.
Neutron: Particles with no charge and are present in
the nuclei of all atoms expect one isotope of
hydrogen.
• Electron: is an extremely small particles with a unit
of negative charge.
1-6 Naming of Inorganic Compounds
Binary Compounds of Metals and Nonmetals
Binary Compounds are those formed between two element.If one
of the elements is a metal and the other a nonmetal,the binary co
mpounds is usually made up of ions; that is, it is a binary ionic co
mpound.To name a binary compound of a metal and a nonmetal
Write the unmodified name of the metal
Then write the name of the nonmetal,modified to end in ide
Name unchanged
NaCl = Sodium chloride
“ide” ending
Ionic compounds, though made up of positive and
negative ions, must be electrically neutral. The net, or total,
charge of the ions in a formula unit must be zero.
Name Symbol Name Symbol
Lithium ion Li+ Chromium (II) ion Cr2+
Sodium ion Na+ Chromium(III) ion Cr3+
Potassium ion K+ Iron(III) ion Fe3+
Rubidium ion Rb+ Iron(II) ion Fe2+
Cesium ion Cs+ Copper(I) ion Cu+
Magnesium Mg2+ Copper(II) ion Cu2+
Calcium ion Ca2+ Mercury(I) ion Hg22+
Barium Ba2+ Mercury(II) ion Hg2+
Aluminum ion Al3+ Tin(II) ion Sn2+
Zinc ion Zn2+ Lead(II) ion Pb2+
Positive ions (cations)
Name symbol Name symbol
Hydride ion H- Iodide ion I-
Fluoride ion F- Oxide ion O2-
Chloride ion Cl- Sulfide ion S2-
Negative ions (anions)
Writing formulas when names of compounds are given
Write formulas for the compounds barium oxide,calcium fluoride,and iron(III) sulfide.SolutionSolution
In each case, identify the cations and charges, based on
periodic table group numbers or on oxidation states appea
ring as Roman numberals in names : Ba+,Ca2+,and Fe3+.The
n identify the anions and their charges:O2-,F-,and S2- .Comb
ine the cations and anions in the relative numbers require
d to produce electrically neutral formula units.
barium oxide: one Babarium oxide: one Ba2+2+and one Oand one O2- 2- = BaO= BaO
calcium fluoride: one Cacalcium fluoride: one Ca2+2+ and two F and two F-- =CaF =CaF22
iron(III) sulfide: two Feiron(III) sulfide: two Fe3+3+ and three S and three S2- 2- = Fe= Fe22SS33
Naming compound when their formulas are given.
Write acceptable name for the compounds Na2S, AlF3, Cu2O.
SolutionSolution
Na2S : sodium sulfide
AlF3 : aluminum fluoride
Cu2O : copper(I) oxide
Binary Compounds of Two NonmetalsBinary Compounds of Two Nonmetals
If the two elements in a binary compound are both nonmetals instead of a metal and a nonmetal, the compound is a molecular compound. The method of naming these compounds is similar to that just discussed. For example
HCl = hydrogen chloride
Generally, we indicate relative numbers of atoms through
prefixes: mono =1,di =2,tri =3, tetra =4,penta =5,hexa =6,
and so on. SO2 = sulfur dioxide
SO3 = sulfur trioxide
B2Br4 = diboron tetrabromideWhen the prefix ends in When the prefix ends in aa or or oo and the element name begins with and the element name begins with
aa or or oo,the final vowel of the prefix is dropped for ease of pronuncia,the final vowel of the prefix is dropped for ease of pronuncia
tion.For example,carbon tion.For example,carbon monmonoxide, not carbon oxide, not carbon monomonooxide,and dioxide,and di
nitrogennitrogen tetrtetroxide,not dinitrogen oxide,not dinitrogen tetratetraoxide.However, PI3 is phospoxide.However, PI3 is phosp
horushorus tri triiodide, not phosphorusiodide, not phosphorus tritriodide.odide.
In both the formula and the name, we write the element with the positive oxidation state first.
Binary Acids
In naming acids we use the prefix hydro followed by the na
me of the other nonmetal modified with an ic ending. The m
ost important binary acids are listed below
HF (aq) = hydrofluoric acid
HCl (aq) = hydrochloric acid
HBr (aq) = hydrobromic acid
HI (aq) = hydroiodic
H2S (aq) = hydrosulfuric acidThe symbol (aq) signifies a substance in aqueous(water) so
lution
Polyatomic Ions
In polyatomic ions, two or more atoms are joined together by covalent bonds. These ions are commonly encountered, especially among the nonmetals.
Name Formula Typical
Cation: Ammonium ion NH4+ NH4Cl
Anions: Cyanide ion CN- NaCN
Hydroxide ion OH- NaOH
Hypochlorite ion ClO- NaClO
Perchlorate ion ClO4- NaClO4
Nitrite ion NO2- NaNO2
Nitrate ion NO3- NaNO3
Phosphate ion PO43- Na3PO4
Hydrogen phosphate ion HPO42- Na2HPO4
Sulfate ion SO42- Na2SO4
Hydrogen sulfate ion HSO4- NaHSO4
Some Common Polyatomic Ions
Oxyacids
The majority of acids are ternary compounds. They contai
n three different elements-hydrogen, and two other nonmetal
s. If one of the nonmetals is oxygen, the acid is called an oxo
acid. The table for naming oxoacids is similar to that outlined
for oxoanions, except that the ending ous is used instead of i
te and ic instead of ate.
Oxidation state
Formula of acid Name of acid Formula of salt
Name of salt
Cl: +1 HClO Hypochlorous acid NaClO Sodium hypochlorite
Cl: +5 HClO3 Chloric acid NaClO3 Sodium chlotate
Cl: +7 HClO4 Perchloric acid NaClO4 Sodium perchlorate
N: +3 HNO2 Nitrous acid NaNO2 Sodium nitrite
N: +5 HNO3 Nitric acid NaNO3 Sodium nitrate
S: +6 H2SO4 Sulfuric acid NaSO4 Sodium sulfate
S: +4 H2SO3 Sulfurous acid NaSO3 Sodium sulfite
Nomenclature of Some Oxoacids and Their Salts
Applying Various Rules in Naming Compounds.
Name the compounds (a)ClO2; (b)Ca(H2PO4)2 Solution
(a) Both Cl and O are nonmetals.ClO2 is a binary molecular compound called chlorine dioxide.
(b) The polyatomic anion HH22POPO44- - is dihydrogen phos is dihydrogen phos
phate ion.Two of these ions are present for every Caphate ion.Two of these ions are present for every Ca2+ 2+ ion in the compound calcium dihydrogen phospha ion in the compound calcium dihydrogen phosphate.te.
ClO2 is not chlorite ion,it carries no net charge
Applying Various Rules in Writing Formulas
Write the formula of the compound (a) tetranitrogen tetrasulf
ide; (b) ammonium chromate; (c) calcium hypochlorite.
Solution
(a)Molecules of this compound consist of four n atoms and four S atoms. The formula is N4S4.
(b) Two ammonium ions (NH4+ )must be present for every chr
omate ion(CrO42-). Place parentheses around NH4
+ ,followed by the subscript 2.The formula is (NH4)2CrO4.
(c) Here there are one Ca2+ and two ClO- ions in a formula unit.This leads to the formula Ca(ClO)2.