Bonding and IMFs
A central atom that is sp3 hybridized could bind up to how many other atoms?
4
How many bonds are in CO2?
4
How many bonds are in SCN-?
4
How many bonds are in H3C2N?
7
If the following crystallize in the same type of structure, which has the lowest lattice energy? A. SrO B. BaO C. BaS D. CaO E. SrS
C. BaS
Which of the following pairs of ions would have the greatest coulombic attraction in a solid compound? A. Mg 2+ S 2- B. Mg 2+ Se 2- C. Mg 2+ O 2-
C. Mg 2+ O 2-
Which of the following compounds contains exactly one unshared pair of valence electrons? A.SiH4 B. H2S C. PH3 D. C2H4
C. PH3 1. Draw you lewis dot structure using S= N-A.
Choose the pair of names and formulae that do not match. A. KNO3, potassium nitrate B. N2O3, Dinitrogen trioxide C. SnCl4, tin (V) chloride D. SiCl4, silicon tetrachloride E. MgSO4, magnesium sulfate
C. SnCl4, tin (v) chloride
Choose the pair of names and formulae that do not match.
N2O5
Every molecule has ______ forces.
dispersion
True or False: All non-polar molecules have non-polar bonds.
false
Which covalent bond is the most polar? A. H---O B. H---N C. H---S D. H---H
A. H---O
Which do you predict to have the strongest C‒N bond? A. HCN B. NH2CH3 C. NHCH2
A. HCN
Name the compound CaBr2.
calcium bromide
The basic fact that determines molecular shapes is that
electron pairs repel each other
Molecular geometry for 6 electron regions with 4 lone pairs. Bond angle.
linear
Calculate the formal charge on N in the molecule NH3?
0
A central atom that is sp2 hybridized can form up to _____ pi bond(s) with a neighboring atom that has a p orbital?
1
How many double bonds are present in the 'best' resonance structure of the phosphate ion?
1
How many total bonds and lone pairs exist in the Lewis structure for chlorine fluoride (ClF)?
1, 6 1. Draw the Lewis dot structure use S= N-A 2. Count up total bonds and lone pairs.
What is the difference in electronegativity between H and F?
1.78 Electronegativites for the atoms involved are: H = 2.20, F = 3.98 Delta EN= 3.98-2.20 = 1.78
How many resonance structures can be drawn for N2O? Disregard any structure with formal charges other than 0, +1, and -1.
2
What is the bond order of the O‒O bond in O2?
2
What total number of valence electrons should appear in the dot formula for the chlorate ion ClO3‒?
26 1. Calculate A as usual. A= 26
The carbonate ion (CO3^2-) has how many resonance configurations?
3
What is the bond order of the C‒C bond in acetylene (ethyne, C2H2)?
3
How many bonds are in CN-?
3 1. Use S=N-A A= 10 N= 16 16-10=6/2=3
How many total bonds and lone pairs exist in the Lewis structure for boron trichloride (BCl3)?
3, 9
For which of the molecules will dipole-dipole interactions be important? A. CO2 B. SO2 C. O2 D. O3
B and D
Which of the following molecules can be involved in hydrogen bonding? H2, HF, CH4, CH3OH
HF, CH3OH
Give the formula for sodium nitrate.
NaNO3
These new hybridized atomic orbitals occupy the correct regions in space that allow for the given __________ geometry around the atom.
electronic
In a covalently bonded compound, electrons are distributed about the entire molecule in such a way that _______________ their energy, relative to their original energies in the separate atoms. The energy of the molecule is lower (more _____________) than the energy of the corresponding separated atoms.
minimizes stable
How many lone pairs of electrons are on nitrogen in NF3?
one
The Valence Bond theory describes the bonds in molecules as arising from the_________ of atomic orbitals centered on the atoms in the molecule. However, to achieve the correct geometries it must often use new __________ orbitals that result from the mixing of some number of pure atomic orbitals.
overlap hybrid
The bond angle of the molecule H2O is less than the tetrahedral bond angle of 109.5˚ because
the repulsion between lone pairs of electrons is greater than the repulsion between bonding pairs.
The electronic arrangement is the same as the molecular shape when
there are no lone pairs
When the central atom in a molecule is covalently bonded to five other atoms and has no valence shell nonbonding electrons, then the arrangement of atoms around the central atom is
trigonal bipyramidal
SCl4 Draw the correct lewis structure. Electronic Geometry Molecular Geometry Polar or NonPolar Lone Pair on Central Atom Lone pair in entire molecule
trigonal bipyramidal see-saw polar one thirteen
Electronic geometry for 3 electron regions with 0 lone pairs. Bond angle.
trigonal planar 120 degrees
The molecular geometry of ammonia (NH3) is
trigonal pyramidal 1. Draw Lewis Structure using S= N-A. 2. Notice you have four regions of electron density around N, so it would be tetrahedral electronically. Tetrahedral with one lone pair will be trigonal pyramidal.
How many unshared electrons and bonding electrons exist around the central atom in ozone (O3)?
two, six
Covalent compounds are generally made up of elements found in which part of the periodic table?
upper right
Resonance is a concept that describes the bonding in molecules...
where there is more than one choice of location for a double or triple bond as deduced from Lewis dot structures. The true bonding is the average over all possible multiple bond locations. Resonance occurs when there is more than one choice of location for a double or triple bond. In resonance, although the arrangement of all possible double bond locations may sometimes mean that a bond has a bond order of 1.5, other possibilities can occur such as 1.333 (1 and a third) bonds. Similarly, a 'triple' bond may have a bond order of 2.5 or 2.333.
Covalent Compound
a tightly held set of neutral atoms forming a neutral molecule
In the CN- ion, what is the formal charge on the C?
-1
Electronic geometry for 2 electron regions with 0 lone pairs. Bond angle.
Linear 180 degrees
Which of these ionic compounds is likely to be more stable? A. LiF, r= 2.01 B. CsI, r= 3.95
A. LiF
Which bond is most polar? A. P-Cl B. Cl-Cl C. I-Cl D. P-I
A. P-Cl
Which of the following compounds are exceptions to the octet rule? Select all of the correct answers. A. PCl5 B. XeF2 C. MgCl2 D. CH4
A. PCl5 B. XeF2
Which pair of elements is most likely to form an ionic compound? A. magnesium and fluorine B. oxygen and chlorine C. Nitrogen and sulfur D. sodium and aluminum
A. magnesium and fluorine
Select all of the following statements that correctly describe the corresponding energies that combine to create the total energy of an ionic bond. A. the lattice energy of the compound B. the ionization energy for the element losing the electron(s) (the cation) C. the electron affinity for the element gaining the electron(s) (the anion) D. The energy gained by sharing electrons between the cation and anion.
A. the lattice energy of the compound B. the ionization energy for the element losing the electron(s) (the cation) C. the electron affinity for the element gaining the electron(s) (the anion)
In which group would you most likely expect the elements to form covalent compounds with incomplete octets? A. 6 B. 3 C. 4 D. 5
B. 3
Which of the following is the name of a positively charged polyatomic ion? A. Oxalate B. Ammonium C. Magnesium D. Carbonate
B. Ammonium
Which of the following contains only covalent bonding and no ionic bonding? A. NaOH B. Na2SO4 C. CCl4 D. Ca(NO3)2
B. CCl4
Which of the following is the best representation of the compound calcium sulfide? A. 3 Ca^2+, 2 S^3 B. Ca^2+, S^2- C. 2 Ca+, S^2 D. Ca^2+, 2 S-
B. Ca^2+, S^2- 1. Calculate the electron configurations for both elements in the compound. Ca= [Ar]4s2 S= [Ne] 3s2 3p4 2. Remember that your metal usually becomes your cation and the nonmetal usually becomes your anion. Ca can give 2, S needs two. 3. Calculate charges on each after the transfer of electrons. Ca2+, S2-
Which of the following ionic compounds would you predict to have the largest lattice energy? A. CaS B. MgO C. NaI D. KI
B. MgO 1. When looking for largest lattice energy, you are essentially looking for the molecule with the smallest cation. 2. Calculate the charges of each by looking at the electron configurations. Ca 2+ S 2- Mg 2+ O 2- Na+ I- K+ I- 3. Na+ and K+ are both bigger than Ca and Mg due to having a higher amount of electrons so they can be eliminated. 4. Remember periodic trends: Atomic radius increases down a group and decreases across a period. Ca is lower on the periodic table than Mg, so it is slightly bigger. MgO is correct.
Which of these ionic compounds is likely to be more stable? A. NaF, r= 2.31 B. MgS, r= 2.6
B. MgS
The Lewis symbol for chlorine would look like:
The letters "Cl" surrounded by 7 dots.
Molecular geometry for 3 electron regions, 1 of which is a lone pair. Bond angle.
Bent or angular Slightly less than 120 degrees
Molecular geometry for 4 electron regions, 2 of which are lone pairs. Bond angle.
Bent or angular. Less than 109 degrees.
The concept of "polarity" is due to A. atoms that are bonded together but have unequal numbers of lone pair electrons. B. similarities in attractions for shared electrons when the electronic and molecular geometries are the same. C. one atom of a bonded pair of atoms exerting a greater attractive force on the shared electrons. D. the optimal Lewis dot structure for any pair of atoms. E. the number of electrons shared by any pair of atoms.
C. one atom of a bonded pair of atoms exerting a greater attractive force on the shared electrons.
Name the compound CaC2O4.
Calcium oxalate
Which of the following demonstrates the formation of an ionic compound involving the elements Na and S? A. Na2^+ + S2^- ⟶NaS B. Na^2+ + Na^2+ + Na^2+ + S^3- + S^3- ⟶ Na3S2 C. Na+ + Na+ + Na+ + S^3- ⟶ Na3S D. Na+ + Na+ + S^2- ⟶ Na2S
D. Na+ + Na+ + S^2- ⟶ Na2S
Which of the following bonds will be the most polar? A. C-H B. Cl-O C. C-N D. S-F
D. S-F
Consider the molecule N2. Each nitrogen atom is sp hybridized. Which answer choice best describes the bonds that exist between the two nitrogen atoms? A. three pi bonds B. two sigma bonds C. two pi bonds D. one sigma bonds and two pi bonds E. three sigma bonds
D. one sigma bonds and two pi bonds
An element E has the electronic configuration [Ne] 3s2 3p1. Write the formula of its compound with sulfate.
E2(SO4)3 Since E has three valence electrons, it forms a +3 ion that is isoelectronic with Ne. Thus, balancing E3+ with SO42-, we get E2(SO4)3.
In which of these compounds would you find ONLY dispersion forces existing between the molecules? I. NH3 II. CH2Cl2 III. CCl4 IV. CO2
III. CCl4 IV. CO2
An element E has the electronic configuration 1s2 2s2 2p4. What is the formula of its compound with lithium?
Li2E 1. Use the electron configuration to figure out the mystery element. 1s2 2s2 2p4= O 2. Calculate the electron configuration of Li. Li= [He]2s1 3. Remember that the metal usually forms the cation while the nonmetal usually forms the anion in ionic compounds. 4. Use electron configuration to figure out how many electrons the metal can give and how many the nonmetal needs. Li has 1 to give. O needs 2. Li2O or as the question wants Li2E
Molecular geometry for 5 electron regions, three of which are lone pairs. Bond angle.
Linear 180 degrees
HCN Draw the correct lewis structure. Electronic Geometry Molecular Geometry Polar or NonPolar Lone pairs in entire molecule
Look up a picture. linear linear polar one
Draw the correct Lewis dot structure for the molecule containing one C, one Cl, and three H atoms.
Look up an image
Electronic geometry for 6 electron regions with 0 lone pairs.
Octahedral
SF6 Draw the correct lewis structure. Electronic Geometry Molecular Geometry Polar or NonPolar Lone Pair on Central Atom Lone pairs in entire molecule Bond angle.
Octahedral Octahedral NonPolar Zero Eighteen 90 degrees 1. Calculate S= N-A A= 48 N= 56 56-48=8/2=4 bonds 2.Put all the electrons on the outer elements. 3. Add in bonds. 4. Remember that 6 electron regions around the central atoms = octahedral. 5. Remember 6 electron regions around the central atom with 0 lone pairs will still be octahedral. 6. Calculate your dipole moments. All will point towards Fluorine and all will cancel out 7. Look at your Lewis Dot Structure for the rest.
Molecular geometry for 5 electron regions one of which is a lone pair. Bond angles.
Seesaw Slightly less than 90 degrees and 120 degrees.
Molecular geometry for 6 electron regions with 2 lone pairs. Bond angle.
Square planar less than 90
Molecular geometry for 6 electron regions with 1 lone pair. Bond angle.
Square pyramidal Slightly less than 90 degrees
Molecular geometry for 5 electron regions, two of which are lone pairs. Bond angles.
T Shape Less than 90 degrees and 120 degrees
Molecular geometry for 6 electron regions with 3 lone pairs. Bond angle.
T shape
Electron geometry for 4 electron regions with 0 lone pairs. Bond angle.
Tetrahedral 109 degrees
Ionic compound
a lattice of positively and negatively charged ions
Electronic geometry for 5 electron regions with 0 lone pairs. Bond angles. Name the two regions of electrons that surround the central atom.
Trigonal bipyramidal 180 degrees (between eq), 120 degrees (between ax) and 90 degrees Equatorial and axial
Molecular geometry for 4 electron regions, one of which is a lone pair. Bond angle.
Trigonal pyramidal Slightly less than 109 degrees
VSEPR stands for
Valence Shell Electron Pair Repulsion
What are the values of x and y for A=Rb and B=I?
X=1 Y= 1 RbI 1. Calculate the electron configuration for both elements. Rb= [Kr]5s1 I= [Kr]5s2 4d10 5p5 2. Remember that the metal will usually form the cation and nonmetal will form the anion. Rb has 1 to give, Iodine needs 1. RbI
What are the values for x and y for A=Na and B=S?
X=2 Y=1 Na2S
What are the values for x and y for A= Al and B=O?
X=2 Y=3 Al2O3
Which is the correct order of increasing bond strength? a. double, single, triple b. single, double, triple c. triple, double, single
b. single, double, triple
You have been asked to draw a molecule that exhibits resonance, in which there are single and double bonds in different locations in the drawings. If you could do an experiment to measure the bond strength of these single and double bonds, you would find that
every time the measurement would give the same bond strength close to the average of a single and double bond.
In general, electronegativity tends to decrease
from top to bottom and from right to left on the periodic table.
In line drawings, hydrogen atoms and lone pairs are ______, which means they are not shown in the drawing.
implicit
Which molecular geometry is possible with 0, 3 or 4 lone pairs?
linear
When determining if a molecule has a dipole moment, there are two important factors that must be considered. First, it must have ___________ __________ bonds. Second, it must have a molecular structure in which the individual dipoles do not cancel. Thus, scientists are primarily concerned with the ____________ of different molecules.
polar covalent shapes
Using your new knowledge of Valence Bond theory please consider this problem: What is the hybridization of the second carbon atom (bolded) in H2CCCH2?
sp
Identify the orbitals used by the bolded atom in acetone (CH3COCH3).
sp2
A molecule has five regions of high electron density around the central atom. One of these is a lone pair and the other four are bonded pairs. What is the hybridization of the central atom?
sp3d
What is the hybridization of Sb in the molecule SbCl5^2-? Antimony (Sb) can accept up to twelve electrons.
sp3d2
Usually, the shorter the bond, the ______ the bond.
stronger
The electronic geometry of NH3 (ammonia) is
tetrahedral
