Studied by 13 people
Levels are …
Sublevels are …
Orbitals are …
Levels are the energy levels/periods/rows, Sublevels are s, p, d, and f, Orbitals are the positions that hold the electrons (# of orbitals half of # of maximum electrons)
Why do ionic bonds tend to have higher melting, boiling points than covalent bonds?
attraction of opposite charge is highly favorable, meaning more energy is needed to break this stability
What is the relationship between an ionic and covalent bond?
Ionic bonds are actually covalent bonds, it's just the electronegativity difference is so much that the electron is transferred completely and not shared
Describe all the covalent bond interactions involving electrons and nucleus
while there's attraction between all electrons and both nuclei, there is also repulsion between nuclei and between electrons, meaning covalent bonds form at the most ideal balance of these forces
What are the x and y axes of the covalent bond graph?
X: internuclear distance in picometers Y: potential energy (Joules)
Explain the relationship between internuclear distance and potential energy
Up to the ideal/favorable point where the covalent bond fully forms, potential energy decreases due to the increasing nuclei-electron attraction, but afterwards, potential energy increases because the atoms are bonded together yet experience greater repulsion of like charges
How would a Cl-Cl bond compare to an H-H bond on the covalent bond graph?
Cl-Cl will have greater internuclear distance due to more shielding, and the shielding means the valence electrons are farther from both nuclei, so less attraction means greater potential energy
Name different levels of covalent bonds longest to shortest
single-double-triple
Bond energy definition
energy required to separate 1 mole of a certain bond
Lattice energy definition
the energy required to form one mole of a solid ionic compound from its gaseous ions
Coulomb's law
lattice energy = constant * (charge in Coulombs of ion #1)(charge in Coulombs of ion #2) over internuclear distance
Which factor has the bigger effect on lattice energy: internuclear distance or charge?
Charge
Describe the photoelectron spectroscopy graph
the y axis is number of e-, and the x axis is the binding energy that decreases as the electrons move further away from the nucleus
Starting from 1s, describe the gap widths seen on photoelectron spectroscopy graphs
As the energy levels and sublevels increase towards the right, the greatest gaps are between energy levels (EX: 1 to 2) and the smaller gaps are between sublevels (EX: s to p)
What does the Born Haber cycle show?
shows the enthalpy changes that occur in each step of separating/forming an ionic compound
Amount of main, possible steps in the Born Haber cycle and exceptions
5; however, some molecules don't require all steps to occur; EX: In MgS, both atoms are already single as opposed to Na + Cl2
Born Haber cycle step 1; +/- enthalpy change
convert any non-gaseous atoms into gaseous state; endothermic
Born Haber cycle step 2; enthalpy change
separate any diatomic atoms into single atoms; endothermic
Born Haber cycle step 3; enthalpy change
ionization energy is needed to remove the electron(s) from the cation; endothermic
Born Haber cycle step 4; enthalpy change
the anion's electron affinity energy attracts the cation's electron(s); exothermic
Born Haber cycle step 5; enthalpy change
the oppositely-charged gaseous ions now combine to form the final solid compound; exothermic
What do you have to note about electron affinity and ionization energies for atoms that can give away/accept 2 or more electrons?
if atoms give away multiple electrons, those electrons have different ionization energies; so atoms that accept multiple electrons have different electron affinity energies specific to each
If you still have leftover electrons, which atoms should most likely get those extra electrons? (3)
-more electronegative atoms
-atoms that currently have a positive formal charge
-atom that is most furthest down a period starting at period 3
Formal charge equation
Polarity definition
the uneven sharing of electrons in molecules due to asymmetrical structure and different electronegativities
Resonance structure definition
structures in which the overall compound charge and position of the atoms stays the same, but the position of some electrons can move around due to not being localized
Hybrid structure 2 aspects
-more stable than the different resonance structures separate
-like a mix of all the resonance structures, so its bond length is between that of single and double bonds
Why can atoms period 3 and beyond expand their octets?
because they have an s, p and d sublevels, not just s and p
Valence Shell Electron Pair Repulsion theory
molecular geometries can be determined thanks to the repulsions between electrons and the greatest minimizations of those repulsions
5 electron domains
linear, trigonal planar, tetrahedral, trigonal bipyramidal, octahedral
Linear geometry angle measure
180˚
Trigonal planar angle measure
120˚
Tetrahedral angle measure and why?
109.5˚; to minimize repulsions, tetrahedral adopts a multi-plane structure which causes wider angles than what would've been in a planar structure
Trigonal bipyramidal angle measureS
-120˚ between the equatorial
-90˚ between the axial and equatorial
Octahedral angle measure
90˚
What is important to note about lone pairs when figuring out why molecular geometries are the certain shape they are?
lone pairs take up more space and thus have a wider range of repulsion, pushing the other electron pairs closer together
Trigonal planar: 2 molecular geometries and requirements for them
-trigonal planar: all electron pairs are bonded
-bent: 1 nonbonded electron pair
Tetrahedral: 3 molecular geometries and requirements for them
-tetrahedral: all bonded
-trigonal planar: 1 unbonded
-bent: 2 unbonded
If trigonal bipyramidal or octahedral happen to have unbonded electron pairs, where do they go?
the equatorial positions
Trigonal bipyramidal 4 molecular geometries and requirements
-trigonal bipyramidal: all bonded
-seesaw: 1 unbonded
-t-shaped: 2 unbonded
-linear: 3 unbonded
Octahedral: 3 molecular geometries and requirements
-octahedral: all bonded
-square pyramidal: 1 unbonded
-square planar: 2 unbonded
What 6 molecular geometries are symmetrical if all attached atoms are the same in each field?
-linear -trigonal planar -square planar -trigonal bipyramidal -octahedral -tetrahedral
Symmetry in regards to trigonal bipyramidal and octahedral structures?
as long as the atoms in the equatorial positions are the same and the atoms in the axial positions are the same, then nonpolar
How to tell if a linear molecular is polar or not?
if atoms on both side of central atom are the same, then nonpolar because of equal dipoles
Polarity arrow trick note #1 for molecule geometries not linear
perform this for every plane of the molecule
Polarity trick #2 for molecular geometries not linear
for each bond, draw the dipole arrow in the appropriate direction
Polarity trick #3 for molecular geometries not linear
assemble the arrows into a cycle; if the cycle can repeat endlessly, it is nonpolar
Hybridization
when an atom is bonding, the s and p orbitals mix together to form hybridized orbitals which correlate with an electron geometry
When does hybridization of an atom not occur?
if atom does not have p orbitals; Ex: H
Along which 3 axes can the 3 p orbitals exist? Their directions?
x and z: horizontal and perpendicular of each other y: vertical
what is the degrees measure between each of the 3 axes?
90˚
s orbital shape
sphere
p orbital shape
pair of lobes (like an 8)
What are hybrid/degenerate orbitals?
the different variations of the mixing of s and p orbitals (of equal energies) which all merge into one final hybridized structure
sp3 hybridization uses _ out of _ p orbitals and makes _ degenerate orbitals
3; 3; 4
sp3 electron geometry
tetrahedral
How many electrons can each hybridized orbital hold up to?
2
how does sp3 apply to molecules that may have the electron geometry tetrahedral, but molecular geometries of something else?
some hybridized orbitals will not be bonded and will just be holding unbonded electrons
What is joined during sp2 hybridization?
1s + any 2 of the 3 p orbitals (doesn't matter which 2 axes you choose)
sp2 makes _ degenerate orbitals and its electron geometry is _____ _____
3; trigonal planar
what is a sigma bond?
a type of covalent bond in which the orbitals of different atoms overlap
does the pi bond form between 2 hybridized or non-hybridized p orbitals?
non-hybridized
how do pi bonds form?
pi bonds form perpendicular to sigma bonds and if the non-hybridized p-orbitals are aligned in the same direction
a single bond formed from 2 overlapping hybridized orbitals is a _____
sigma bond
generally, a double bond consists of ____
a sigma and pi bond
generally, a triple bonds consists of _______
a sigma bond and 2 pi bonds
how many p orbitals does sp hybridization use?
1 out of 3
sp hybridization forms _ degenerate bonds and its electron geometry is ______
2; linear
Note 
Flashcard (30)