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- Sodium azide is a shock-sensitive compound that releases N2 upon physical impact. The compound is used in automobile airbags. The azide ion is N3-. (a) Draw the Lewis structure of the azide ion that minimizes the formal charge (it does not form a triangle). Is it linear or bent?
문제 1
문제 3a
For each molecule (a)–(f), indicate how many different electron-domain geometries are consistent with the molecular geometry shown. a.
문제 4c
The molecule shown here is difluoromethane 1CH2F22, which is used as a refrigerant called R-32. (c) If the molecule is polar, which of the following describes the direction of the overall dipole moment vector in the molecule: (i) from the carbon atom toward a fluorine atom, (ii) from the carbon atom to a point midway between the fluorine atoms, (iii) from the carbon atom to a point midway between the hydrogen atoms, or (iv) from the carbon atom toward a hydrogen atom?
문제 5c
The following plot shows the potential energy of two Cl atoms as a function of the distance between them. (c) If the Cl2 molecule is compressed under higher and higher pressure, does the Cl–Cl bond become stronger or weaker?
문제 6a
The orbital diagram that follows presents the final step in the formation of hybrid orbitals by a silicon atom. (a) Which of the following best describes what took place before the step pictured in the diagram: (i) Two 3p electrons became unpaired, (ii) An electron was promoted from the 2p orbital to the 3s orbital, or (iii) An electron was promoted from the 3s orbital to the 3p orbital?
문제 6b
The orbital diagram that follows presents the final step in the formation of hybrid orbitals by a silicon atom. (b) What type of hybrid orbital is produced in this hybridization?
문제 7a
In the hydrocarbon
(a) What is the hybridization at each carbon atom in the molecule?
문제 7b
In the hydrocarbon (b) How many s bonds are there in the molecule?
문제 7d
In the hydrocarbon
(d) Identify all the 120° bond angles in the molecule.
문제 8a
The drawing below shows the overlap of two hybrid orbitals to form a bond in a hydrocarbon. (a) Which of the following types of bonds is being formed: (i) C¬C s, (ii) C¬C p, or (iii) C¬H s?
문제 8b
The drawing below shows the overlap of two hybrid orbitals to form a bond in a hydrocarbon. (b) Which of the following could be the identity of the hydrocarbon: (i) CH4, (ii) C2H6, (iii) C2H4, or (iv) C2H2?
문제 9e
The molecule shown below is called furan. It is represented in typical shorthand way for organic molecules, with hydrogen atoms not shown, and each of the 4 vertices representing a carbon atom.
(e) The C—C—C bond angles in furan are much smaller than those in benzene. The likely reason is which of the following: (i) The hybridization of the carbon atoms in furan is different from that in benzene, (ii) Furan does not have another resonance structure equivalent to the one above, or (iii) The atoms in a five-membered ring are forced to adopt smaller angles than in a six-membered ring.
문제 10a
The following is part of a molecular orbital energy-level diagram for MOs constructed from 1s atomic orbitals.
(a) What labels do we use for the two MOs shown?
문제 11a3
For each of these contour representations of molecular orbitals, identify (a) the atomic orbitals (s or p) used to construct the MO (iii)
문제 11a1
For each of these contour representations of molecular orbitals, identify (a) the atomic orbitals (s or p) used to construct the MO (i)
문제 11b3
For each of these contour representations of molecular orbitals, identify (b) the type of MO (s or p) (iii)
문제 11b1
For each of these contour representations of molecular orbitals, identify (b) the type of MO (s or p) (i)
문제 11c1
For each of these contour representations of molecular orbitals, identify (c) whether the MO is bonding or antibonding (i)
문제 13a
(a) An AB2 molecule is linear. How many nonbonding electron pairs are around the A atom from this information?
문제 13b
(b) How many nonbonding electrons surround the Xe in XeF2?
문제 13c
(c) Is XeF2 linear
문제 14a
(a) Boron trichloride 1BCl32 and the carbonate ion 1CO3 2- 2 are both described as trigonal. What does this indicate about their bond angles?
문제 14b
(b) The PCl3 molecule is trigonal pyramidal, while ICl3 is T-shaped. Which of these molecules is flat?
- How does a trigonal pyramid differ from a tetrahedron so far as molecular geometry is concerned?
문제 15
문제 16
Describe the bond angles to be found in each of the following molecular structures: (a) trigonal planar, (b) tetrahedral, (c) octahedral, (d) linear.
문제 17a,c
(a) An AB6 molecule has no lone pairs of electrons on the A atom. What is its molecular geometry? (c) For the AB4 molecule in part (b), predict the molecular geometry.
문제 17b
(b) An AB4 molecule has two lone pairs of electrons on the A atom (in addition to the four B atoms). What is the electron-domain geometry around the A atom?
문제 18
Would you expect the nonbonding electron-pair domain in NCl3 to be greater or smaller in size than the corresponding one in PCl3?
- In which of these molecules or ions does the presence of nonbonding electron pairs produce an effect on the molecular shape? (a) CO2, (b) CH2Br2, (c) OF2, (d) BCl3, (e) SF6.
문제 19
문제 20
In which of the following molecules can you confidently predict the bond angles about the central atom, and for which would you be a bit uncertain? Explain in each case. (a) H2S, (b) BCl3, (c) CH3I, (d) CBr4, (e) TeBr4.