CHAPTER 6 Problems (Problems 1-11 cover material for Exam 2)
1) Which of the following bonds will have the smaller value for bond length?
a) C-O or C=O b) N=N or NºN c) C-O or C-S
2) (Burdge, 6.20) Classify the following bonds as nonpolar covalent, polar covalent, or ionic. Explain.
a) The CC bond in H3CCH3 c) The NB bond in H3NBCl3
b) The KI bond in KI d) The CF bond in CF4
3) (Burdge, 6.12) The radical species ClO has a dipole moment of 1.24 D and a Cl-O bond distance of 1.57 Å. Determine the magnitude of the partial charges in ClO.
4) (Burdge, 6.14) The measured dipole moment of bromine monofluoride, BrF, is 1.42 D, and the Br-F bond distance is 1.76 Å. Determine the percent ionic character in the bond in BrF.
5) Arrange the following bonds in order from least polar to most polar: C-C, C-Cl, C-H.
6) Arrange the following atoms in order from lowest electronegativity to highest electronegativity. a) As, N, P b) Ca, Cs, K c) Ge O, Se
7) Compare the properties of ionic compounds and covalent compounds.
8) Draw the Lewis structure for each of the following molecules. Based on your structure, identify the total number of lone pair electrons and bonding electrons for the underlined atom in each molecule. a) HBr, b) H2S, c) CH4
9) Draw Lewis structures for the following molecules: a) CHCl3, b) NH3, c) CH3CN
10) (Burdge, 6.22) Draw Lewis structures for the following molecules or ions:
a) NCl3 c) H2O2 e) CN-
b) OCS d) CH3COO- f) CH3CH2NH3+
11) (Burdge, 6.74 a,b,c) Draw Lewis structures for the following organic molecules
a) tetrafluoroethylene, C2F4
b) propane, C3H8
c) butadiene, CH2CHCHCH2
12) (Burdge, 6.29) Draw Lewis structures for the following ions. Show formal charge.
a) NO2+ c) S22-
b) SCN- d) ClF2+
13) (Burdge, 6.34) Draw three resonance structures for the chlorate ion (ClO3-). Show formal charges.
14) (Burdge, 6.38) Draw three resonance structures for the molecule NNO, where N is the central atom. Indicate formal charges, and rank the resonance structures in order of most important to least important.
15) (Burdge, 6.50) Until the early 1960s the noble gases were not known to form compounds. Since then, a few compounds of Kr, Xe, and Rn - and one compound of Ar - have been made in the laboratory. Draw Lewis structures for the following molecules. In each case Xe is the central atom.
a) XeF2 c) XeF6 e) XeO2F2
b) XeF4 d) XeOF4
16) Draw the Lewis structure for a) BCl3, b) NO
17) (Burdge, 6.58) Write Lewis structures for BrF3, ClF5, and IF7. Identify the structures where the octet rule is not obeyed.
18) (Burdge, 6.57) Draw two resonance structures for sulfurous acid (H2SO3) - one that obeys the octet rule, the other that minimizes formal charge. Determine the formal charges for each atom in each resonance structure.
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