Types of Problems Likely to be on the Exam! - Chapter 9

9.4

Describe the bonding of C in the guanidinium cation, CN3H6+.  Carbon is the central atom.
1) Carbon forms two double bonds
2) Carbon forms four single bonds
3) Carbon forms one double bond and two single bonds
4) Carbon forms one triple bond and one single bond
5) Carbon forms one triple bond and two single bonds

The Lewis dot representation of formic acid, HCO2H, has
1) an incomplete octet for the C atom
2) four single bonds
3) three single bonds and one double bond
4) two double bonds
5) two equally plausible resonance forms

The skeleton for the, azide anion, N3-, is NNN. The Lewis dotrepresentation for the azide anion has
1) formal charges of zero on all three N atoms
2) two single bonds
3) one single bond and one double bond
4) two double bonds
5) two equally plausible resonance forms

The number of lone electron pairs in the N2 molecule is ___.
 1) 1
 2) 2
 3) 3
 4) 4
 5) 5

9.5

Which of the following pairs of elements would be most likely to form an ionic compound?
1) Cl and I
2) Al and K
3) Cl and Mg
4) C and S
5) Al and Mg

A polar covalent bond would form in which one of the following pairs of atoms?
 1) Cl and Cl
 2) Si and Si
 3) Ca and Cl
 4) Cs and Br
 5) P and Cl

9.6 

Give the number of bonding electron pairs around the central atom in a molecule of urea (CO(NH2)2)
1) 0
2) 1
3) 2
4) 3
5) 4

The total number of bonding electrons in a molecule of formaldehyde (H2CO) is
 1) 3
 2) 4
 3) 6
 4) 8
 5) 18

9.7

Assuming the octet rule is obeyed, how many covalent bonds will a nitrogen atom form to give a formal charge of zero?
 1) 1
 2) 2
 3) 3
 4) 4
 5) 5

In the best Lewis structure for the fulminate ion, CNO-, what is the formal charge on the central
nitrogen atom?
1. +2
2. +1
3. 0
4. -1
5. -2

9.9

Which of the following does not follow the octet rule?
1) CCl4
2) BF3
3) H2O
4) CO2
5) C2H4

Which response includes all the molecules below that do not follow the octet rule?
(1) H2S (2) BCl3 (3) PH3 (4) SF4
 1) (2) and (4)
 2) (2) and (3)
 3) (1) and (2)
 4) (3) and (4)
 5) (1) and (4)

Answer Key:
9.4: 3,3,4,2
9.5: ?, 5
9.6: 5,4
9.7: 3,2
9.9: 2,1