Multiple Choice
Which of the following is not a property of metals caused by metallic bonding?
a. malleability
b. ductility
c. low boiling points
d. conductivity
c. low boiling points
Which of the following describes a metallic bond?
a. Two valence electrons being shared to create an octet
b. A sea of freely floating electrons around nearby cations
c. One valence electron being transferred to another atom
d. A bond in which one atom is much more electronegative than the other
b. A sea of freely floating electrons around nearby cations
Why are diatomic molecules of elements, such as H2, Cl2, N2, and Br2 always nonpolar?
a. Polar molecules must have 3 atoms.
b. The 2 atoms have the same number of valence electrons.
c. The two atoms have the same electronegativity.
d. The 2 atoms do not have any lone pairs of electrons.
c. The two atoms have the same electronegativity.
Determine the shape:
PCl3
trigonal pyramidal
Determine the shape:
CO2
Which of the following molecules would have the strongest bonds (hint: consider the number of bonds between each molecule)?
a. F2
b. O2
c. N2
d. H2
c. N2
Nitrogen has 5 valence electrons. How many lone pairs of electrons are there in the compound NH3?
a. one
b. two
c. three
d. seven
a. one
What is the molecular geometry for carbon tetrachloride?
a. linear
b. trigonal planar
c. tetrahedral
d. trigonal pyramidal
c. tetrahedral
Why is the shape of a molecule important to chemists?
it dictates its function, reactivity, and physical properties
Explain why it’s important to understand whether a stain is polar or nonpolar in order to remove it.
Understanding a stain's polarity is crucial because the principle of "like dissolves like" dictates that polar stains (like sugar, wine) dissolve in polar solvents (water), while nonpolar stains (like oil, grease) need nonpolar solvents (alcohol, specific degreasers) or surfactants (soap) to be removed, allowing you to choose the right cleaning agent for effective dissolution and lifting from the surface.
Carbon is in group 14 (IV-A) of the periodic table. Following the octet rule, how many covalent bonds will carbon form?
a. one
b. two
c. three
d. four
d. four
How many bonds are shared by two oxygen atoms in an oxygen gas molecule (O2)?
a. two
b. four
c. six
d. eight
a. two
What is the molecular geometry for carbon dioxide?
a. linear
b. trigonal planar
c. tetrahedral
d. bent
a. linear
What is the difference between an ionic bond and a covalent bond?
ionic - transfer
covalent - sharing
What is the difference between a nonpolar covalent bond and a polar covalent bond?
Polar covalent bonds have unequal electron sharing due to large electronegativity differences, creating positive/negative poles (like in water, H₂O), while nonpolar covalent bonds have equal sharing between atoms with similar electronegativity, resulting in no poles (like in O₂, Cl₂, or C-H bonds)
How many electrons are in a double bond?
a. two
b. four
c. six
d. eight
b. four
Which of the following structures is 3-dimensional?
a. ball-and-stick model c. Lewis structure
b. molecular formula d. structural formula
a. ball-and-stick model
What is the shape of boron trifluoride?
a. linear
b. trigonal planar
c. tetrahedral
d. trigonal pyramidal
b. trigonal planar
Using the electronegativity scale, arrange the following molecules in order from the most nonpolar to the most polar molecules. Show your work.
HF, HCl, NO, CO
NO, HCl, CO, HF
Using the electronegativity scale, arrange the following molecules in order from the most nonpolar to the most polar molecules. Show your work.
OH, PCl, CN, N2
N2, CN, PCl, OH
Which of these molecular shapes has the smallest bond angle?
a. linear
b. trigonal planar
c. trigonal pyramidal
d. bent
d. bent
Which of the following is NOT true in regards to cleaning materials with soap?
a. Soap has both hydrophilic and hydrophobic portions.
b. Soap is attracted to both polar and nonpolar substances.
c. Soap can be used to clean large protein stains like blood and grass.
d. Soap causes “scum” when mixed with hard water, while detergents do not.
c. Soap can be used to clean large protein stains like blood and grass.
What is the molecular shape of ammonia (NH3)?
a. linear
b. trigonal planar
c. tetrahedral
d. trigonal pyramidal
d. trigonal pyramidal
Which type of intermolecular forces occur in ALL types of covalently bonded molecules?
dispersion forces
If a liquid had a very high boiling point, what type of intermolecular forces would you assume existed between the liquid molecules?
hydrogen bonding