Inorganic Exam 1
What is the Pauli Exclusion Principle?
No two electrons can have identical quantum numbers
Why did the discovery of Argon pose a problem for Mendeleev's periodic table?
Noble gases didn't exist so it didn't fit into a group. Also, because Mendeleev's table was based on measured atomic mass, argon (39.9) should have been placed between potassium (39.1) and calcium (40.1).
Define polar covalent
Two atoms with a large difference in electronegativity
What are the only two radioactive elements to exist in significant quantities on earth?
Uranium and thorium
BP = 2, LP = 1
V
BP = 2, LP = 2
V
Potential units
V (joules/coloumb)
scan rate
V/s
IMF's/Solubility of small covalent molecules
Weak IMF's, soluble is many solvents but not water
Why is iron the highest number formed in stellar processes?
With nuclei up to 26 protons, nuclear fusion is an exothermic process and is thus favored. Beyond this point, fusion is endothermic and requires the energy from a supernova explosion to happen.
Why is the radius of Germanium almost the same as silicon?
With the poorly shielding 3d orbitals having been filled corresponding to the added protons, the effective nuclear charge on the outer (4p) electrons will be increased; hence the covalent radius will decrease.
Zeff formula
Z - σ
_____ is a measure of how much of the positive charge of the nucleus is felt by each e⁻
Zeff
How to find Q
[products] / [reactants]
Weak metal characteristics
a little less metallic?
Bronsted-lowry base definition
accepts H+
Lewis Acid definition
accepts electrons
Examples of Polar Aprotic Solvents
acetonitrile, dimethylsulfoxide, dimethylformamide, "ionic liquids".
Add (acid/water) to (acid/water)
acid to water
As charge increases, aquo ligands become more ___________.
acidic
Most non-metal oxides are ________.
acidic
define zwitterion
adjacent charges
Group 1's name
alkali metals
Group 2's name
alkaline earth metals
Possible n values
an integer value (1,2,3....n)
What is l?
angular momentum quantum number
Acidity trend between anions and cations
anion < neutral < cation (most acidic)
Dative bonds sometimes represented with _______
arrows
What defines the type of element?
atomic number / protons
Negative potentials are good/bad
bad
Most metal oxides are _______.
basic
Why do we have to take metals to 3D conductivity?
because graphite is a good electrical conductor in 2D
Ionic properties
brittle, high melting points, conduct electricity, typically soluble in water, and involves very strongly and weakly electronegative elements
The only liquid non-metal at SATP
bromine
Group 16's name
chalcogens
charge density formula
charge / volume
No band gap =
conductor
One advantage and one disadvantage of the long form of the periodic table
correct order but too long
what is l=2's shape?
d
Electrostatic interactions sometimes represented with ___________.
dashed lines
As cation size __________, aquo ligands become more acidic.
decreases
Bronsted-lowry acid definition
donates H+
Lewis base definition
donates electrons
Metal characteristics
ductility (stretchable), malleability (squishible), and highly conductive
When Zeff increases, it's (easier/harder) to add an electron
easier
metallic
electron sea/gas
What is the aufbau Principle?
electrons fill in the lowest energy orbital first
Semi-metal characteristsics
even less metallic - tend to form small molecules rather than metallic sheets
What is l=3's shape?
f
VSEPR limitations
fails for isoelectronic species an fails to accurately predict geometries for transition metal complexes
Non-polar solvents are good at dissolving _____ and ______. (Hint: think dry cleaning)
fats and oils
∆G < 0 Rxn moves _________
forward
extreme steric bulk
frustrated lewis pairs
What is l=4's shape?
g
Define what weak nuclear force does
governs how things decary
Define what gravity does
governs particle attraction based on mass - doesn't rely on charge
Elements in the same ______ have similar properties.
group
What is l=5's shape?
h
Covalent radius
half distance between the nuclei of two atoms of the same element
Van der waals Radius
half distance between the nuclei of two neighboring atoms
Group 17's name
halogens
When Zeff increases, it's (easier/harder) to remove an electron
harder
Examples of non-polar solvents
hexane, diethyl ether, benzene, toluene, chloroform, xenon(!)
4s is always ______ in energy than 3d in ions
higher
HOMO
highest occupied molecular orbital
Frost Diagram: high and on the left of the plot =
highly oxidizing
Frost Diagram: high and on the right of the plot =
highly reducing
Define what strong nuclear force does
holds the nuclei together
Periodic table study websites
http://www.sporcle.com/games/g/elements http://www.ilpi.com/genchem/periodicquiz.html
∆E =
hv
Secondary coordination sphere:
hydrogen-bonding interactions similar to bulk water, stabilizing an acid.
What is l=6's shape?
i
Impurity band =
impurity semi-conductor
More negative charge will _________ the affinity for a positively charged proton.
increase
Arrhenius-Oswald acid definition
increase the [H+] in aqueous solution
Arrhenius-Oswald base definition
increase the [OH-] in aqueous solution
Large band gap =
insulator
Small band gap =
intrinsic semi-conductor
Zeff and radius are (directly/inversely) proportional.
inversely
More polar solvents, especially polar protic solvents: good at solubilizing _______.
ions
∆G = 0 Rxn _________
is at equilibrium
Entropy formula
klnw (k = boltzmann constant, w = # of possible states)
Beyond the 126 protons of _______, the number of positive charges in the nucleus becomes too large to maintain nuclear stability.
lead
Elements above ____ are unstable.
lead
Zeff increases from ____ to ____ on the period table
left to right
increasing electron affinity goes from
left to right and bottom to top
increasing ionization energy goes from
left to right and bottom to top
Heavier elements are _______ abundant
less - many are radioactive
BP = 2, LP = 0
linear
LUMO
lowest unoccupied molecular orbital
What is ml?
magnetic quantum numbers
Ionic
mainly electrostatic (large differences in electronegativity)
Covalent
mainly through orbital overlap
What is Hund's Rule?
maximize total spin and orbital angular momentum
Current x time =
moles of e- and Faraday's constant
Elements with even atomic numbers are _____ abundant.
more
higher diaelectric constant =
more polar
Primary coordination sphere:
most dramatic impact on reactivity and properties
Non-polar solvents, especially aprotic solvents: good for solubilizing ______________.
neutral small molecules
What defines the isotope of the element?
neutrons
∆H>0, ∆S<0: ∆G>0
never spontaneous
Group 18's name
noble gases
Non-metal characteristics
non-conducting and often liquids or gases
Types of solvents
non-polar, polar aprotic, polar protic
What is the atomic number made of?
number of protons in the nucleus (aka number of electrons)
Possible l Values
o to (n-1)
6 bonding pairs geometry
octahedral
BP = 6, LP = 0
octahedral
Elements with (even/odd) numbers of protons have an abundance of about 1/10th that of their (even/odd)-numbered neighbors.
odd; even
Know the different radiuses
okay
Know the name of the groups and regions of the table
okay
Look at powerpoint for calculation of Zeff
okay
Look up relationship between element names and symbols
okay
Look up the differences between the dirac and schrodinger wave equations
okay
what is l=1's shape?
p
The behavior of an unpaired electron is named _________.
paramagnetism
Elements in the same _____ have different properties, but have related orbital structure with different numbers of protons and electrons.
period
What period often exceeds the octet rule?
period 3
Group 15's name
pnictogens
What is n?
principle quantum numbers
Secondary coordination sphere can play a huge role in chemistry:
protein reactions are often dramatically influenced.
What two things are in the nucleus?
protons and neutrons
F =
q/n (charge / electrons)
Solubility is based on
reactant solvation and reactant IMF's
∆G > 0 Rxn moves _________
reverse
Atomic radius increases from _____ to _____ and from ____ to _____.
right to left; top to bottom
what is l=0's shape?
s
BP = 4, LP = 1
seesaw
Does a period go up and down or side to side?
side to side
SOMO
singly occupied molecular orbital
What is ms?
spin quantum number
∆H<0, ∆S>0: ∆G<0
spontaneous at any temperature
BP = 4, LP = 2
square planar
BP = 5, LP = 1
square-based pyramidal
Would you rather have s² and f₉ or s¹ and f¹⁰?
s¹ and f¹⁰
Would you rather have s² and f⁴ or s¹ and f⁵?
s¹ and f⁵
4 bonding pairs geometry
tetrahedral
BP = 4, LP = 0
tetrahedral
What is Z?
the actual nuclear charge
What happens when bound-water protons become more acidic?
they deprotonate!
5 bonding pairs geometry
trigonal bipyramidal
BP = 5, LP = 0
trigonal bypyramidal
3 bonding pairs geometry
trigonal planar
BP = 3, LP = 0
trigonal planar
BP = 3, LP = 1
trigonal pyramidal
Define pure covalent
two atoms with similar electronegativity
Paramagnetic behavior in a magnetic field indicates the presence of ________.
unpaired electrons
Does a group go up and down or side to side?
up and down
IMF's/Solubility of metals and network covalent
very strong bonding forces, not typically soluble
Examples of polar protic solvents
water, alcohols (methanol, ethanol), amines (ammonia, methylamine)
Define unstable
when left alone, the pure elemental material decomposes — usually occurs by radioactive decay.
Polar Aprotic Solvents
• Solvation through dispersion forces, polarization, and cation stabilization. • Good for some polar covalent small molecules and some ionic lattices.
VSEPR Theory (Gillespie-Nyholm Theory)
•Minimize formal charges (FC = nvalence - (nnon-bonded - nbonds)) • Ensure full octets (if possible) • Don't exceed an octet (unless d-orbitals are available) • Minimize overall charge • Avoid adjacent charges (zwitterions)
∆G formula
∆G = ∆G° + RtlnQ
Bond Order Formula
(# of bonding e - # of antibonding e)/2
Possible ms values
+1/2 and -1/2
Possible ml values
-1, 0, 1
Define what electromagnetic force is/does
-Combination of Electric, and magnetic effects (relationship between electric and magnetic fields) -Relies on sign and magnitude of charge -Electric attraction/repulsion are responsible for holding molecules together
Polar Protic Solvents
-Solvation through polarization, cation stabilization, and anion stabilization (H bond). • Good for ionic lattices, sometime unable to dissolve non-polar small molecules. • Good for hydrophilic materials
E =
-∆G° / nF
If you're calculating Zeff for a 1s electron, when n=n you subtract ____.
0.3
How many nodes does a p orbital have?
1
Slater's Rules
1. Each electron in orbitals of greater principle quantum number (in shells beyond the shell of interest) contributes 0. 2. (a) If e- of interest is in a s- or p-orbital, each e- with the same principle quantum number contributes 0.35. (b) If e- of interest is in a d or f orbital, the d or f e-'s contribute 0.35 but the s and p e⁻'s (of same quantum number) contribute 1.0. 3. (a) If e- of interest is in a s or p orbital, each e- in the (n-1) quantum level contributes 0.85. (b) If e- of interest is in a d or f orbital, then they contribute 1.0. 4. Each e- in an orbital of smaller principle quantum number contributes 1.0.
Predicting metal acidity rules:
1. Smaller cations = more acidic 2. More highly charged cations = more acidic 3. electronegativity
Find the potential using free energies instead of just standard potentials
1. ∆G° = nFE° 2. Add the two 3. Plug back into -∆G°FV/nF
The highest atomic number for which stable isotopes exist
126 (lead)
How many nodes does a d orbital have?
2
Completed quantum levels contain how many electrons? (List all the possibilities)
2, 10, 18, 36, 54, and 86
List the most stable nuclear configurations "magic numbers"
2, 8, 20, 28, 50, 82, 126
Suggest the number of neutrons in the most common isotope of Calcium
20 - doubly magic
All ionic transition metal complexes fill in order ___, ___, ____.
3d, 4s, 4p
Yttrium, element 39, exists in nature with only one isotope. What do you think the number of neutrons is?
50 - neutrons > protons and 50 is closest "magic" number above 39
How many stable elements are there?
80
What is the highest atomic number for which stable isotopes exist?
82 - lead
Faraday's constant
96485 C/mol
effective nuclear charge definition
Actual nuclear charge experienced by an electron in an atom.
k =
Ae^(-Ea/RT) (A = frequency factor)
Valence bond theory
Assumes that covalent bonds are formed when atomic orbitals on different atoms overlap and electrons are shared.
Semi-metals
B, Si, Ge, As, Sb, Te
Weak Metals
Be, Al, Zn, Ga, Sn, Pb, Bi, and Po
What are the eight chemically weak metals?
Beryllium, Aluminum, Zinc, Gallium, Tin, Lead, Bismuth, and polonium.
Suggest why polonium-210 and astatine-211 are the isotopes of those elements with the longest half-lives?
Both polonium-210 and astatine-211 have 126 neutrons, the filled-shell value, giving additional stability to the isotopes.
What is the only liquid nonmetal at SATP?
Bromine
Why s, p, d, f?
Derived from atomic spectral lines of alkali metals
Why is thermal conductivity a poor guide to determining metals?
Diamond, a carbon (nonmetal) allotrope, has the highest thermal conductivity of all substances.
Father of the periodic table
Dmitri Medeleev
rare earth metals
Elements scandium, yttrium, and lanthanum through lutetium
What makes something a metalloid?
Elements with some chemical and/or physical properties that resemble metals and others that resemble nonmetals. Alternative answer: elements with properties that are intermediate between those expected for a metal and those expected for a nonmetal
Define Bertrand's Rule
For almost all essential elements, there is an optimum amount for intake. Above or below this amount typically causes harmful effects.
What is the best criterion for metal?
High three-dimensional electrical conductivity
Covalent properties
Rely on matching orbital energy, orbital overlap, and symmetry
What are the rare earth metals?
Sc, Y, La-Lu
Why is metallic luster a poor guide to determining metals?
Several nonmetals, such as iodine, and some compounds, such as FeS2 fool's gold, have metallic lusters
What does s, p, d, and f stand for?
Sharp, Principle, Diffuse, Fundamental
Non-polar solvents
Solvation through dispersion forces, Good for non-polar covalent small molecules, and Hydrophobic or lypophilic substances
IMF's/Solubility of ionic lattices
Strong IMF's and soluble in water
What are the 4 fundamental forces?
Strong nuclear force, weak nuclear force, gravity and electromagnetic force
BP = 3, LP = 2
T
What is the only transition metal for which no stable isotopes are known?
Technetium
Only transition metal for which no stable isotopes are known
Telhnetium
Explain why the atomic mass of cobalt is greater than that of nickel even though the atomic number of cobalt is less than that of nickel
The common isotope of cobalt has more neutrons than that of nickel
Why is the atomic mass of cobalt bigger than nickel's?
The common isotope of cobalt has more neutrons than that of nickel, hence the atomic mass will be higher. In fact, the only natural isotope of cobalt has 32 neutrons, while nickel has two common isotopes, one with 30 neutrons (68 percent), the other with 32 neutrons (26 percent).
Why must the heavy elements on this planet have been formed from the very early supernovas that exploded?
The only way in which high-atomic-number elements can be formed is by means of the energy from supernova explosions (iron is the highest atomic-number element that is formed exothermically by fusion reactions). Hence these elements on this planet must have been formed from such an explosion billions of years ago.
What is σ?
The screening constant
Why does Hund's rule work?
The two electrons paired and occupying the same orbital would be least favorable, because the pairing energy would be necessary to overcome the repulsive forces. Paired but in different orbitals also comes with an energy cost because there is a finite probability that the electrons will occupy the same volume of space, again resulting in a repulsive energy factor. With parallel spins there is zero probability that the electrons will occupy the same volume of space; hence this is the lowest energy condition
Two reasons why the discovery of argon posed problems for the original mendeleev table
There was no space for argon because it did not fit into any of the then known groups (the noble gas group was then unknown). Also, because Mendeleev's table was based on measured atomic mass (atomic number was unknown at the time), argon (39.9) should have been placed between potassium (39.1) and calcium (40.1).