Download Midterm Review Sheet

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Chemistry-434: Mid-term Review
Chapters 1 - 6
People:
1. Aristotle – Continuous Theory of Matter: matter could be divided and subdivided into smaller and
smaller pieces without limit.
2. Democritus – Discontinuous Theory of Matter: matter could be divided in half repeatedly until
eventually it could no longer be divided. This smallest piece was called the atom.
3. Lavoisier - Law of conservation of mass.
4. Proust - Law of definite composition.
5. Dalton - Law of multiple proportions also developed atomic theory, much of which is still in use
today.
6. Crookes - using Crookes' tube discovered "cathode rays" as negative particles/radiation. This was the
first evidence of electrons.
7. Thomson – determined: 1) that cathode rays were actually streams of negatively charged particles
called electrons (could be deflected by a magnetic or electric field); and, 2) the charge/mass ratio of
the electron.
8. Max Plank – discovered that atoms and molecules emit energy only in certain discrete quantities or
bundles called quanta (or quantum) and not continuously as previously thought. A single bundle is a
quanta. Plank's equation shows the relationship between frequency and energy.
E = h where h = 6.63 x 10-34 J-s (Planck’s constant)
9. Einstein - explained the photoelectric effect (Nobel Prize), developed his theory of relativity, and the
relationship between mass and energy E = mc2. Used the term “photon” to describe one quantum
(particle) of light or radiation.
10. Millikan - determined the charge and mass (using Thomson's charge/mass ratio) of an electron.
11. Rutherford - discovered the nucleus and proton.
12. Moseley - determined that the charge in successive elements increases by one and was the basis for
listing the elements in the periodic table by increasing atomic number.
13. Bohr - developed an atomic model for hydrogen, which explained its emission spectra; orbits, ground
state, excited state, energy levels; Lyman, Balmer, Paschen, and Brackett series in the hydrogen
atom.
14. de Broglie - determined that if light waves can behave like a stream of particles (photons) then
particles such as electrons can behave like light. "Duality of nature" (matter-wave concept): waves as
particles; particles as waves. This concept fits especially well for particles the size of an electron.
Explains why only certain frequencies or energies of electrons are possible.
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15. Schrodinger - developed his wave equation and laid the foundation for modern quantum theory.
Schrodinger orbitals replaced Bohr's orbits. Solution to Schrodinger's wave equation are the quantum
numbers.
16. Heisenberg – develops his uncertainty principle: it is not possible to know both the velocity and
position of a particle (electron) at the same time.
17. Chadwick - discovered the neutron, the last of the atomic particles.
18. Cannizaro - developed a method for determining atomic masses.
19. Mendeleev - father of the periodic table. He classified elements by increasing atomic mass and by
properties (properties taking precedent); able to now look for trends.
Laws, Rules, and Principles:
1. Law of Conservation of Mass (Lavoisier) - matter can not be created or destroyed in ordinary
chemical or physical changes.
2. Law of Definite Composition (Proust) - a chemical compound contains the same elements in exactly
the same proportions by mass regardless of the size of the sample or source of the compound.
3. Law of Multiple Proportions (Dalton) - if two elements can combine to form more than one
compound, the masses of the second element that combine with a fixed mass of the first element are in
ratios of small whole numbers.
4. Aufbau Principle - the rule that an electron occupies the lowest energy
level (orbital) that can receive it.
5. Hund's Rule - orbitals of equal energy are each occupied by one electron before any orbital is
occupied by a second electron; spins of single electrons are parallel.
6. Pauli Exclusion Principle - no two electrons in the same atom can have the same set of four quantum
numbers (i.e. direction of spin must be opposite for all paired electrons).
7. Heisenberg Uncertainty Principle - it is not possible to know both the speed and position of a particle
at the same time.
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Equations and Calculations:
1. Absolute error and percent error.
% error = OV-TV x 100%
TV
absolute error = OV-TV
2. Accuracy and precision:
a) accuracy - tells how close a measurement is to the true value of the quantity that was measured.
b) precision - refers to how closely two or more measurements of the same quantity agree with one
another.
3. Density:
D = m/V  moles  particles  mass
4. Heat gained or lost:
q = mcpT
q = Joules; m = mass in grams;
T = change in temperature (T = Tf - Ti) in oC.
cp = specific heat in J/goC:
5. Energy, frequency, and wavelength:
E = h
E = energy in Joules of one photon of radiation/light
h = Plank's constant (6.63 x 10-34 Js);
 = frequency of the radiation in Hz.
c = 
c = speed of light (3.0 x 108 m/s);
 = wavelength of the electromagnetic radiation in meters;
 = frequency of the radiation in Hz (cycles/s).
En = -RH(1/n2) RH = Rydberg constant (2.18 x 10-18 J)
n = main energy level or principle quantum number
E = h = hc/ = RH(1/ni2 – 1/nf2) change in energy between two principal quantum numbers
6. Temperature scales and conversions: oF = 1.8C + 32;
7. Misc. formulas:
a. volume of a cylinder:
b. volume of a sphere:
c. volume of a square:
d. volume of a rectangle:
o
C = (oF - 32)/1.8
K = oC + 273
v = r2h
v = 4/3r3
v = s3
v=lxwxh
8. Stoichiometry: calculations involving mass  moles  particles  volume  moles  mass
9. average atomic weight calculation
10. percent composition
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Concepts:
1. Determining the number of significant figures.
2. Multiplying and dividing with exponents (scientific notation).
3. Adding and subtracting with exponents.
4. SI base (fundamental) units
5. Prefixes and conversions
6. Scientific Method (hypothesis, theory, experiments, and law)
7. Classification of matter (homogeneous and heterogeneous), physical and chemical properties and
changes; extensive and intensive physical properties.
8. Heat, energy (kinetic and potential), and temperature; exothermic and endothermic reactions.
9. Electron filling order and configurations (order of fill); energy levels, sublevels, orbitals, maximum
number of electrons.
10. Layout of the periodic table - s, p, d, and f blocks; alkali metals, alkali earth metals, halogens, noble
gases, lanthanide (rare earth metals) series, actinide series, groups and charges, general properties of
metals, nonmetals, and metalloids, monatomioc, diatomic, and polyatomic elements. Periodic
trends - electronegativity, ionization energy, electron affinity, and atomic/ionic radius.
11. Atomic particles - protons, neutrons, electrons, atomic number, mass number, relative mass;
isotopes, relative atomic mass, average atomic mass.
12. Bonds; ionic, covalent, metallic, polar, non-polar, intermolecular forces; molecular geometry
(VSEPR).
Handouts: Classification of matter, development of atomic theory; periodic trends, quantum numbers and
filling order, periodic table misc., VSEPR summary, bonding and molecular forces .