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Problem 73c
Draw a picture that shows all three 2p orbitals on one atom and all three 2p orbitals on another atom. (c) How many antibonding orbitals, and of what type can be made from the two sets of 2p orbitals?
Problem 74a
Indicate whether each statement is true or false. (a) p orbitals can only make σ or σ* molecular orbitals.
Problem 74b
Indicate whether each statement is true or false. (b) The probability is always 0% for finding an electron in an antibonding orbital.
Problem 74c
Indicate whether each statement is true or false. (c) Molecules containing electrons that occupy antibonding orbitals must be unstable.
Problem 74d
Indicate whether each statement is true or false. (d) Electrons cannot occupy a nonbonding orbital.
- According to molecular orbital theory, would Be2 be expected to exist? Explain. Would Be2+ be expected to exist? Explain. What are the relationships among bond order, bond length, and bond energy?
Problem 75
- Explain the following: (c) The O22 + ion has a stronger O—O bond than O2 itself.
Problem 76
- How would we describe a substance that contains only paired electrons and is weakly repelled by a magnetic field? Which of the following ions would you expect to possess similar characteristics: H2-, Ne2+, F2, O22 +?
Problem 77
Problem 79d
Using Figures 9.35 and 9.43 as guides, draw the molecular orbital electron configuration for (d) Ne22 +. In each case indicate whether the addition of an electron to the ion would increase or decrease the bond order of the species.
Problem 80b
If we assume that the energy-level diagrams for homonuclear diatomic molecules shown in Figure 9.43 can be applied to heteronuclear diatomic molecules and ions, predict the bond order and magnetic behavior of (b) NO+.
Problem 80d
If we assume that the energy-level diagrams for homonuclear diatomic molecules shown in Figure 9.43 can be applied to heteronuclear diatomic molecules and ions, predict the bond order and magnetic behavior of (d) ClF.
Problem 81a
Determine the electron configurations for CN+, CN, and CN-. (a) Which species has the strongest C¬N bond?
Problem 81b
Determine the electron configurations for CN+, CN, and CN-. (b) Which species, if any, has unpaired electrons?
Problem 82a
(a) The nitric oxide molecule, NO, readily loses one electron to form the NO+ ion. Which of the following is the best explanation of why this happens: (i) Oxygen is more electronegative than nitrogen, (ii) The highest energy electron in NO lies in a π2p* molecular orbital, or (iii) The π2p* MO in NO is completely filled.
Problem 82c2
(c) With what neutral homonuclear diatomic molecules are the NO+ and NO- ions isoelectronic (same number of electrons)? With what neutral homonuclear diatomic molecule is the NO- ion isoelectronic (same number of electrons)?
Problem 83a
Consider the molecular orbitals of the P2 molecule. Assume that the MOs of diatomics from the third row of the periodic table are analogous to those from the second row. (a) Which valence atomic orbitals of P are used to construct the MOs of P2?
Problem 83c
Consider the molecular orbitals of the P2 molecule. Assume that the MOs of diatomics from the third row of the periodic table are analogous to those from the second row. (c) For the P2 molecule, how many electrons occupy the MO in the figure?
Problem 84a
The iodine bromide molecule, IBr, is an interhalogen compound. Assume that the molecular orbitals of IBr are analogous to the homonuclear diatomic molecule F2. (a) Which valence atomic orbitals of I and of Br are used to construct the MOs of IBr?
Problem 84c
The iodine bromide molecule, IBr, is an interhalogen compound. Assume that the molecular orbitals of IBr are analogous to the homonuclear diatomic molecule F2. (c) One of the valence MOs of IBr is sketched here. Why are the atomic orbital contributions to this MO different in size?
- (b) When applying the VSEPR model, we count a double or triple bond as a single electron domain. Why is this justified?
Problem 85
Problem 86a
An AB2 molecule is described as having a tetrahedral geometry. (a) How many nonbonding domains are on atom A?
Problem 86b
An AB2 molecule is described as having a tetrahedral geometry. (b) Based on the information given, which of the following is the molecular geometry of the molecule: (i) linear, (ii) bent, (iii) trigonal planar, or (iv) tetrahedral?
Problem 87a
Consider the following XF4 ions: PF4-, BrF4-, ClF4+, and AlF4-. (a) Which of the ions have more than an octet of electrons around the central atom?
Problem 87b
Consider the following XF4 ions: PF4-, BrF4-, ClF4+, and AlF4-. (b) For which of the ions will the electron-domain and molecular geometries be the same?
Problem 87c
Consider the following XF4 ions: PF4-, BrF4-, ClF4+, and AlF4-. (c) Which of the ions will have an octahedral electron-domain geometry?
Problem 88a
Consider the molecule PF4Cl. (a) Draw a Lewis structure for the molecule, and predict its electron-domain geometry.
Problem 88c
Consider the molecule PF4Cl. (c) Predict the molecular geometry of PF4Cl. How did your answer for part (b) influence your answer here in part (c)?
Problem 88d
Consider the molecule PF4Cl. (d) Would you expect the molecule to distort from its ideal electron-domain geometry? If so, how would it distort?
- Although I3- is a known ion, F3- is not. (d) Yet another classmate says F3- does not exist because F is too small to make bonds to more than one atom. Is this classmate possibly correct?
Problem 89
Problem 90
Fill in the blank spaces in the following chart. If the molecule column is blank, find an example that fulfills the conditions of the rest of the row. Molecule Electron-Domain Hybridization Dipole Geometry of Central Atom Moment? Yes or No CO2 sp3 Yes sp3 No Trigonal planar No SF4 Octahedral No sp2 Yes Trigonal bipyramidal No XeF2