Molecular Shape, Polarity & The VSEPR Model
angle of a trigonal planar(AS)
What is 120 degrees?
This theory explains how covalent bonds are formed by using principles of atomic orbital overlapping and concentrated regions of electron density (HK).
What is valence-bond theory?
Sigma bonds
What is when line joining the two nuclei passes through the middle of the overlap region?(DM)
Instead of combining in the region between the nuclei, the atomic wave orbital functions cancel each other in this region, leaving the greatest electron density on opposite sides of the nuclei(SD)
What is the antibonding molecular orbital?(SD)
Usually do not contribute significantly to bonding in molecule formation(SD)
What are the core electrons?(SD)
The electron domains for non-bonding electron pairs exert greater ______ forces than bonding electron.
What is repulsive?(AS)
The hybridization of one s orbital and one p orbital would give this hybrid orbital set with this molecular geometry (HK).
What is two sp hybrid orbitals with a linear molecular geometry?
electrons in a molecule, ion or solid metal that are not associated with a single atom or one covalent bond. Delocalized electrons are contained within an orbital that extends over several adjacent atoms.
Define what delocalized electrons mean.(DM)
1/2(no. of bonding electrons- no. of antibonding electrons) (SD)
What is bond order?(SD)
Both the pi2p and pi2p* molecular orbitals are...(SD)
What is doubly degenerate?(SD)
a T-shape is...(AS)
What is the molecular geometry of a molecule that has a total of 5 electron domains, 3 of which are bonding pairs while the other 2 are non-bonding pairs?
Molecules with four sp3 hybrid orbitals and zero nonbonding electron pairs have this bond angle. (HK)
What is 109.5 degrees?
hybridization and number of each bond for C2H4
What is sp3d and 5 bonds(DM)?
the presence of an equal number of bonding and antibonding electrons means the bond order is...(SD)
What is zero?(SD)
O2^2- has __ unpaired electrons and is _________(paramagnetic or not paramagnetic) (SD)
What is zero and not paramagnetic? (SD)
molecular geometry of XeF2..(AS)
What is linear from trigonal bipyramidal?
The observed bond length between any two bonded nuclei in a covalent bond is the distance at which these two forces are balanced (HK).
What is attractive forces between unlike charges (nuclei and electrons) and repulsive forces between like charges (electron-electron and nucleus-nucleus)?
number of sigma and pie bonds present in C2H6 (DM)
What are 7 sigma and 0 pi bonds?
the bond order of He2^+ (DM)
What is 1/2?
Bond order for CN+, CN, CN-.(SD)
What is 2.5, 2.0, 3.0?(SD)
number of resonance structures and polarity of SO2(AS)
What is 3 and polar?
This force between two atoms is responsible for the sharp increase in potential energy at very short inter-nuclear distances. (HK)
What are electrostatic repulsions between atomic nuclei?
Suppose that silicon could form molecules that are precisely the analogs of ethane,ethylene, and acetylene. Describe the bonding about Si in terms of hybrid orbitals(DM)
What is the Si analogs would have the same hybridization as the C carbon atoms in each molecule of sp^3, sp^2, sp?
This is what happens (and why) when an H2^- ion is excited by light so that an electron moves from a lower-energy to a higher-energy molecular orbital. (HK)
What is the ion decomposes because its bond order is -1/2 and the ion is unstable relative to two separate H atoms?
Using average bond enhtalpies from table 8.4, find the enthalpy change for S8-->4S2(SD)
What is 456 KJ?(SD)