Bonding exercises
Monday, November 14, 2022
2:46 AM
Explain how σ and π bonds are similar and how they are different.
2.
Draw a curve that describes the energy of a system with H and Cl atoms at varying
distances. Then, find the minimum energy of this curve two ways.
(a) Use the bond energy found in to calculate the energy for one single HCl bond (Hint:
How many bonds are in a mole?)
(b) Use the enthalpy of reaction and the bond energies for H 2 and Cl2 to solve for the
energy of one mole of HCl bonds.
H2(g)+Cl2(g)⇌2HCl(g)ΔH∘rxn=−184.7 kJ/molH2(g)
+Cl2(g)⇌2HCl(g)ΔHrxn°=−184.7 kJ/mol
3.
Explain why bonds occur at specific average bond distances instead of the atoms
approaching each other infinitely close.
4.
Use valence bond theory to explain the bonding in F2, HF, and ClBr. Sketch the overlap
of the atomic orbitals involved in the bonds.
5.
Use valence bond theory to explain the bonding in O2. Sketch the overlap of the atomic
orbitals involved in the bonds in O2.
6.
How many σ and π bonds are present in the molecule HCN?
7.
A friend tells you N2 has three π bonds due to overlap of the three p-orbitals on each N
atom. Do you agree?
8.
Draw the Lewis structures for CO2 and CO, and predict the number of σ and π bonds for
each molecule.
(a) CO2
(b) CO
Hybrid atomic orbitals
9.
Why is the concept of hybridization required in valence bond theory?
10.
Give the shape that describes each hybrid orbital set:
(a) sp2
(b) sp3d
(c) sp
(d) sp3d2
11.
Explain why a carbon atom cannot form five bonds using sp3d hybrid orbitals.
12.
What is the hybridization of the central atom in each of the following?
(a) BeH2
(b) SF6
(c) PO43−PO43−
(d) PCl5
, 13.
A molecule with the formula AB3 could have one of four different shapes. Give the shape
and the hybridization of the central A atom for each.
14.
Methionine, CH3SCH2CH2CH(NH2)CO2H, is an amino acid found in proteins. The Lewis
structure of this compound is shown below. What is the hybridization type of each
carbon, oxygen, the nitrogen, and the sulfur?
15.
Sulfuric acid is manufactured by a series of reactions represented by the following
equations:
S8(s)+8O2(g)⟶8SO2(g)S8(s)+8O2(g)⟶8SO2(g)
2SO2(g)+O2(g)⟶2SO3(g)2SO2(g)+O2(g)⟶2SO3(g)
SO3(g)+H2O(l)⟶H2SO4(l)SO3(g)+H2O(l)⟶H2SO4(l)
Draw a Lewis structure, predict the molecular geometry by VSEPR, and determine the
hybridization of sulfur for the following:
(a) circular S8 molecule
(b) SO2 molecule
(c) SO3 molecule
(d) H2SO4 molecule (the hydrogen atoms are bonded to oxygen atoms)
16.
Two important industrial chemicals, ethene, C2H4, and propene, C3H6, are produced by
the steam (or thermal) cracking process:
2C3H8(g)⟶C2H4(g)+C3H6(g)+CH4(g)+H2(g)2C3H8(g)⟶C2H4(g)
+C3H6(g)+CH4(g)+H2(g)
For each of the four carbon compounds, do the following:
(a) Draw a Lewis structure.
(b) Predict the geometry about the carbon atom.
(c) Determine the hybridization of each type of carbon atom.
17.
Analysis of a compound indicates that it contains 77.55% Xe and 22.45% F by mass.
(a) What is the empirical formula for this compound? (Assume this is also the molecular
formula in responding to the remaining parts of this exercise).
(b) Write a Lewis structure for the compound.
(c) Predict the shape of the molecules of the compound.
(d) What hybridization is consistent with the shape you predicted?
18.
Monday, November 14, 2022
2:46 AM
Explain how σ and π bonds are similar and how they are different.
2.
Draw a curve that describes the energy of a system with H and Cl atoms at varying
distances. Then, find the minimum energy of this curve two ways.
(a) Use the bond energy found in to calculate the energy for one single HCl bond (Hint:
How many bonds are in a mole?)
(b) Use the enthalpy of reaction and the bond energies for H 2 and Cl2 to solve for the
energy of one mole of HCl bonds.
H2(g)+Cl2(g)⇌2HCl(g)ΔH∘rxn=−184.7 kJ/molH2(g)
+Cl2(g)⇌2HCl(g)ΔHrxn°=−184.7 kJ/mol
3.
Explain why bonds occur at specific average bond distances instead of the atoms
approaching each other infinitely close.
4.
Use valence bond theory to explain the bonding in F2, HF, and ClBr. Sketch the overlap
of the atomic orbitals involved in the bonds.
5.
Use valence bond theory to explain the bonding in O2. Sketch the overlap of the atomic
orbitals involved in the bonds in O2.
6.
How many σ and π bonds are present in the molecule HCN?
7.
A friend tells you N2 has three π bonds due to overlap of the three p-orbitals on each N
atom. Do you agree?
8.
Draw the Lewis structures for CO2 and CO, and predict the number of σ and π bonds for
each molecule.
(a) CO2
(b) CO
Hybrid atomic orbitals
9.
Why is the concept of hybridization required in valence bond theory?
10.
Give the shape that describes each hybrid orbital set:
(a) sp2
(b) sp3d
(c) sp
(d) sp3d2
11.
Explain why a carbon atom cannot form five bonds using sp3d hybrid orbitals.
12.
What is the hybridization of the central atom in each of the following?
(a) BeH2
(b) SF6
(c) PO43−PO43−
(d) PCl5
, 13.
A molecule with the formula AB3 could have one of four different shapes. Give the shape
and the hybridization of the central A atom for each.
14.
Methionine, CH3SCH2CH2CH(NH2)CO2H, is an amino acid found in proteins. The Lewis
structure of this compound is shown below. What is the hybridization type of each
carbon, oxygen, the nitrogen, and the sulfur?
15.
Sulfuric acid is manufactured by a series of reactions represented by the following
equations:
S8(s)+8O2(g)⟶8SO2(g)S8(s)+8O2(g)⟶8SO2(g)
2SO2(g)+O2(g)⟶2SO3(g)2SO2(g)+O2(g)⟶2SO3(g)
SO3(g)+H2O(l)⟶H2SO4(l)SO3(g)+H2O(l)⟶H2SO4(l)
Draw a Lewis structure, predict the molecular geometry by VSEPR, and determine the
hybridization of sulfur for the following:
(a) circular S8 molecule
(b) SO2 molecule
(c) SO3 molecule
(d) H2SO4 molecule (the hydrogen atoms are bonded to oxygen atoms)
16.
Two important industrial chemicals, ethene, C2H4, and propene, C3H6, are produced by
the steam (or thermal) cracking process:
2C3H8(g)⟶C2H4(g)+C3H6(g)+CH4(g)+H2(g)2C3H8(g)⟶C2H4(g)
+C3H6(g)+CH4(g)+H2(g)
For each of the four carbon compounds, do the following:
(a) Draw a Lewis structure.
(b) Predict the geometry about the carbon atom.
(c) Determine the hybridization of each type of carbon atom.
17.
Analysis of a compound indicates that it contains 77.55% Xe and 22.45% F by mass.
(a) What is the empirical formula for this compound? (Assume this is also the molecular
formula in responding to the remaining parts of this exercise).
(b) Write a Lewis structure for the compound.
(c) Predict the shape of the molecules of the compound.
(d) What hybridization is consistent with the shape you predicted?
18.
