chapter two - 國立臺北科技大學chpro/chem/chap2.pdf · three important laws (continued) law...
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Chapter Two:
ATOMS, MOLECULES, AND IONS
p38
2-1 The Early History of Chemistryp39
2-2 Fundamental Chemical Lawsp41
Three Important Laws
Law of conservation of mass
Mass is neither created nor destroyed
Law of definite proportion
A given compound always contains exactly
the same proportion of elements by mass
Three Important Laws (continued)
Law of multiple proportions
When two elements form a series of compounds,
the ratios of the masses of the second element
that combine with 1 gram of the first element can
always be reduced to small whole numbers.
Ex 2.1 Illustrating the Law of MultipleProportions
P42
The following data were collected for several compounds of nitrogen
and oxygen:
Sow how these data illustrate the law of multiple proportions.Solution:
2-3 Dalton’s Atomic Theoryp43
Each element is made up of tiny particles called
atoms.
Dalton’s Atomic Theory (1808)
Dalton’s Atomic Theory (1808) (continued)
The atoms of a given element are identical; the
atoms of different elements are different in
some fundamental way or ways.
Dalton’s Atomic Theory (continued)
Chemical compounds are formed when atoms
combine with each other. A given compound
always has the same relative numbers and types of
atoms.
Dalton’s Atomic Theory (continued)
Chemical reactions involve reorganization of the atoms
- changes in the way they are bound together. The
atoms themselves are not changed in a chemical
reaction.
Avogadro’s Hypothesis (1811)
At the same temperature and pressure, equal volumes of
different gases contain the same number of particles.
5 liters of oxygen
5 liters of nitrogen
Same number of particles!
p43Representing Gay-Lussac’s Results
p45Representing Gay-Lussac’s Results
2-4 Early Experiments toCharacterize the Atom
p45
The Electron
Figure 2.7 A Cathode-ray tube. The fast-moving electrons excite thegas in the tube, causing a glow between the electrodes. The green colorin the photo is due to the response of the screen (coated with zincsulfide) to the electron beam.
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Early Experiments to Characterize the Atom
J. J. Thomson - postulated the existence of
electrons using cathode ray tubes.
Ernest Rutherford - explained the nuclear atom,
containing a dense nucleus with electrons
traveling around the nucleus at a large distance.
Cathode Ray Tube
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Milliken Oil Drop Experiment
2-5 The Modern View of AtomicStructure
The atom contains:
electrons
protons: found in the nucleus; positive charge
equal in magnitude to the electron’s negative
charge.
neutrons: found in the nucleus; no charge;
virtually same mass as a proton.
p49
p49The Nuclear Atom
Radioactivity
Rutherford’s Gold Foil Experiment
Nuclear Atom Viewed in Cross Sectionp50
Two Isotopes of Sodiump50
Ex 2.2 Writing the Symbols for AtomsP52
Write the symbol for the atom that has an atomic number
of 9 and a mass number of 19. How many electrons and
how many neutrons does this atom have?Solution:
2-6 Molecules and Ions p52
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Formation of Ionic Compounds
p54
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Molecular vs. Ionic Compounds
Covalent Bonding
2-7 An Introduction to the PeriodicTable
p55
The Periodic Tablep56
2-8 Naming Simple Compoundsp57
Binary Ionic Compounds (Type I)p58
Naming Binary Ionic Compoundsp58
Ex 2.3 Naming Type I Binary CompoundsP58
Name each binary compound.
a. CsF b. AlCl3 c. LiH
Solution
P59
Ex 2.4 Formulas from Names forType I Binary Compounds
Given the following systematic names, write the formula
foe each compound:
a. Potassium iodide, b. Calcium oxide, c. Gallium bromide
Solution:
Binary Ionic Compounds (Type II)
p59Formulas from Names
Ex 2.5 Naming Type II Binary CompoundsP59
1. Give the systematic name for each of the following
compounds:
a. CuCl b. HgO c. Fe2O3
2. Given the following systematic names, write the
formula for each compound:
a. Manganese(IV) oxide
b. Lead(II) chloride
Solution: p60
Ex 2.6 Naming Binary CompoundsP60
1. Give the systematic name for each of the following
compounds:
a. CoBr2 b. CaCl2 c. Al2O3
2. Given the following systematic names, write the
formula for each compound:
a. Chromium(III) chloride
b. Gallium iodide
S0lution:
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Figure 2.22 The common cations and anions
p62
Ex 2.7 Naming Compounds ContainingPolyatomic Ions
P62
1. Give the systematic name for each of the followingcompounds:
a. Na2SO4, b. KH2PO4, c. Fe(NO3)3,d. Mn(OH)2, e. Na2SO3, f. Na2CO3
2. Given the following systematic names, write the formulafor each compound:a. Sodium hydrogen carbonate,b. Cesium perchloratec. Sodium hypochlorited. Sodium selenatee. Potassium bromate
Solution: p63
Ex 7.7 Solution (continued)
p63
Binary Covalent Compounds (Type III)p63
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N2O
NO
Ex 2.8 Naming Type III BinaryCompounds
P64
1. Name each of the following compounds:
a. PCl5, b. PCl3, c. SO2
2. From the following systematic names, write the formulafor each compound:
a. Sulfur hexafluoride, b. Sulfur trioxide,c. Carbon dioxide
Solution:p64
Flowchart for Naming Binary Compounds
Figure 2.23
p65
Overall Strategy for NamingChemical Compounds
p65
Figure 2.34
P65
Ex 2.9 Naming Various Types ofCompounds
1. Give the systematic name for each of the following
compounds:
a. P4O10, b. Nb2O5, c. Li2O2, d. Ti(NO3)4
2. Given the following systematic names, write the
formula for each compound:
a. Vanadium(V) fluoride, b. Dioxygen difluoride,
c. Rubidium peroxide, d. Gallium oxide
Solution:
p66
Ex 2.9 Solution (continued):p66
Flowchart for Naming Acids
Figure 2.25
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