Chapter 5 – Covalent Compounds
1) Which of the following elements does exist as a diatomic molecule?
A) Hydrogen
B) Nitrogen
C) Iodine
D) Oxygen
E) All of the above
2) There are __________ lone pairs and __________ unpaired electrons in the Lewis symbol for
a sulfur atom.
A) 4, 2
B) 2, 4
C) 2, 2
D) 4, 3
E) 1, 3
3) How many unpaired electrons are there in the Lewis structures of a N3- ion?
A) 0
B) 1
C) 2
D) 3
E) This cannot be predicted.
4) How many single covalent bonds must a silicon atom form to have a complete octet in its
valence shell?
A) 3
B) 4
C) 1
D) 2
E) 0
5) A __________ covalent bond between the same two atoms is the weakest.
A) Single
B) Double
C) Triple
D) They are all the same length.
E) Strong
6) How many chlorine atoms must bond to phosphorous to give it an octet of valence electrons?
A) 1
B) 2
C) 3
D) 4
E) 5
7) A double bond consists of __________ pairs of electrons shared between two atoms.
A) 1
B) 2
C) 3
D) 4
E) 6
8) What is the maximum number of double bonds that a carbon atom can form?
A) 0
B) 1
C) 2
D) 3
E) 4
9) In a covalently bonded molecule, the number of electrons that an atom shares with others is
usually equal to
A) Electrons needed to form a single bond
B) Electrons in its valence shell
C) 8 electrons
D) 4 electrons
E) Needed to give it a noble gas arrangement
10) The correct name of the compound NCl3 is
A) Nitrogen chloride
B) Trinitrogen chloride
C) Nitrogen (III) chloride
D) Ammonia
E) Nitrogen trichloride
11) The correct name for the compound N2O3 is
A) Nitrogen oxide
B) Nitrogen trioxide
C) Dinitrogen trioxide
D) Dinitrogen oxide
E) Dinitride trioxide
12) What is the formula of carbon tetrachloride?
A) CClO4
B) CCl4
C) C4Cl
D) CCl3
E) C2Cl4
13) The ability of an atom to attract the shared electrons in a covalent bond is its
A) Electronegativity
B) Bonding ability
C) Polarity
D) Ionic character
E) Nonpolarity
14) Which of the following substances contains a nonpolar covalent bond?
A) H2O
B) HCl
C) NH3
D) MgF2
E) N2
15) How many lone pairs of electrons are in the Lewis structure of SF4?
A) 0
B) 1
C) 2
D) 3
E) 4
16) Choose the best Lewis structure for OCl2
A)
B)
D)
E)
C)
17) Choose the best Lewis structure for CH2Cl2
A)
B)
D)
E)
C)
18) Which of the following compounds contains at least one polar covalent bond?
A) CaF2
B) H3COH
C) C2H2
D) BH3
E) O2
19) Which of the following molecules is not polar?
A) CCl4
B) HCl
C) HCN
D) NH3
E) NO2
20) What is the shape of the boron trichloride molecule?
A) Linear
B) Square
C) Pyramidal
D) Tetrahedral
E) Planar triangle
21) The water molecule has a dipole with the negative portion
A) Localized between the hydrogen atoms
B) Pointing toward the oxygen atom.
C) Localized on one of the hydrogens
D) Pointing from the oxygen through the hydrogen atoms
E) Surrounding the molecule
22) What is the shape of the ammonia molecule ( NH3 )?
A) Bent
B) Square
C) Pyramidal
D) Tetrahedral
E) Planar triangle
23) What is the shape of the carbon dioxide (CO2 ) molecule?
A) Linear
B) Angular with 120° angle
C) Pyramidal
D) Tetrahedral
E) Bent
24) What is the shape of the ( H2S) molecule?
A) Linear
B) Tetrahedral
C) Pyramidal
D) Bent
E) Trigonal planar
25) In the molecule below, which atom has the largest partial negative charge __________?
A) Cl
B) F
C) Br
D) I
E) C
26) Given the electronegativities below, which covalent single bond is most polar?
Element:
H
C
N
O
Electronegativity:
2.1
2.5
3.0 3.5
A) C-H
B) N-H
C) O-H
D) O-C
E) O-N
27) The Lewis structure of PH3 shows __________ nonbonding electron pair(s) on P.
A) 0
B) 1
C) 2
D) 3
E) This cannot be determined from the data given.
28) How many equivalent resonance forms can be drawn for CO32-?
A) 1
B) 2
C) 3
D) 4
E) 0
29) The type of compound that is most likely to contain a covalent bond is __________.
A) One that is composed of a metal from the far left of the periodic table and a nonmetal
from the far right of the periodic table
B) A solid metal
C) One that is composed of only nonmetals
D) Held together by the electrostatic forces between oppositely charged ions
E) There is no general rule to predict covalency in bonds.
30) The Lewis structure of N2H2 shows __________.
A) A nitrogen-nitrogen triple bond
B) A nitrogen-nitrogen single bond
C) Each nitrogen has one nonbonding electron pair
D) Each nitrogen has two nonbonding electron pairs
E) Each hydrogen has one nonbonding electron pair
31) Which of the following compounds violates the octet rule in their Lewis structures?
A) NF3
B) IF3
C) PF3
D) SbF3