Polarity
What causes polarity?
Polarity can be within bonds or within molecules as a whole. It is caused by an unequal sharing of electrons in covalent bonds.
What type of bond uses hybridized orbitals and what kind uses regular orbitals?
Sigma bonds and unshared pairs of electrons use hybridized orbitals. Pi bonds use regular p orbitals.
Compare the geometry of BH3 and NH3. Would they have the same geometry or different? Why?
They both have three single sigma bonds branching from the center atom. The difference is that nitrogen in NH3 has an unshared pair of electrons which changes it from a trigonal planar shape to a trigonal pyramidal shape.
Which of the compounds would have the highest bond disassociation energy?
H2 B2 NO+ O2 Cl2
NO+ has a triple bond which is the strongest covalent bond due to the extra sharing of electrons.
What are the weakest and strongest IMFs?
Weakest - LDF
Strongest - Hydrogen bonds
Which of these would be polar?
BeCl2 COH2 O3 O2 Cl2 CH4 NH3 BF3
COH2 NH3
When the reaction, CH4 + O2 -> CO2 + H2O occurs, does the hybridization of carbon atoms change? If so, what were the orbital hybridizations before and after the reaction?
It does change. The bonds change from a set of 4 sp3 orbitals to 2 sp orbitals and 2 p orbitals.
Which of these compounds would have two or more resonance structures?
BeCl2 COH2 O3 O2 Cl2 CH4 NH3 BF3
O3
Which of the following only has single bonds?
BeCl2 COH2 O3 O2 Cl2 CH4 NH3 BF3
BeCl2 Cl2 CH4 NH3 BF3
Which of these compounds would have the strongest intermolecular forces?
BeCl2 COH2 O3 O2 Cl2 CH4 NH3 BF3
NH3
Which of these bonds would be the least polar?
Oxygen and Nitrogen are right next to each other on the periodic table. Polarity is caused by a difference in electronegativity and since they are so close, their electronegative is also similar leading to a bond that is not very polar.
What is the hybridization of the carbon and nitrogen in a cyanide molecule (CN-)?
There is a triple bond with each atom having 1 unshared pair of electrons. This causes the bond to made of 1 sp orbital and 2 p orbitals. The unshared electrons are also a sp orbital.
Which of the following would have no unshared pairs of electrons on the central atom?
BeCl2 COH2 O3 O2 Cl2 CH4 NH3 BF3
COH2 BeCl2 CH4 BF3
Would N2 or O2 have a shorter bond length?
N2
Which of these would have the strongest IMFs?
CH4 C4H10 Kr CS2
All of these are nonpolar molecules or single atoms which means they all tie for LDFs as the strongest IMF. The one with the greatest surface area will have the strongest LDF which is C4H10.
Which of these would be polar?
BeCl2 COH2 O3 O2 Cl2 CH4 NH3 BF3
COH2, O3, NH3
Which of these would have an oxygen with an sp2 hybridized orbital?
BeCl2 COH2 O3 O2 Cl2 CH4 NH3 BF3
O3 O2
H2O and SO2 both have bent geometrical structures. Which one would have the smaller bond angles and how do you know?
H2O. SO2 only has one unshared pair of electrons and H2O has two. These unshared pairs of electrons take up more space than a single bond and cause the other bonds angles to be reduced. Thus, the one with the more unshared pairs of electrons will have the smallest bond angle.
Which of the following ion pairs would have the highest lattice energy? (The hardest to separate)
Be and O have +2 and -2 charges respectively. This is tied with Ca and S but Be and O are smaller atoms and thus are closer together in the ionic bond. The lower distance and the increased charges lead to it having the highest lattice energy
Which of the following ion pairs would have the highest lattice energy? (The hardest to separate)
Be and O have +2 and -2 charges respectively. This is tied with Ca and S but Be and O are smaller atoms and thus are closer together in the ionic bond. The lower distance and the increased charges lead to it having the highest lattice energy.
Which of these would have polar covalent bonds but is a nonpolar molecule?
BeCl2 COH2 O3 O2 Cl2 CH4 NH3 BF3
BF3
What would be the hybridization of the orbitals in the carbons in C2H4?
sp2
Categorize each of these compounds into bent, linear, trigonal pyramidal, tetrahedral, and trigonal planar geometry?
BeCl2 COH2 O3 O2 Cl2 CH4 NH3 BF3
Bent:O3
linear:BeCl2, O2, Cl2
Trigonal Pyramidal: NH3
Tetrahedral: CH4
Trigonal Planar:COH2, BF3
Which of these compounds would have the smallest bond angles and the largest bond angles?
BeCl2 COH2 O3 O2 Cl2 CH4 NH3 BF3
Smallest: NH3
largest: BeCl2
What are all the IMFs that CHN has?
LDF and Dipole-Dipole