UNE Chem 1011 EXAM Questions With
Complete Solutions
Intermolecular forces (IMFs) correct answer: the forces of
attraction between molecules of covalent compounds (weak)
Intramolecular forces correct answer: forces within molecules.
Forces caused by the attraction and repulsion of charged
particles (strong)
Dispersion forces correct answer: present in all molecules
attractions between molecules caused by the electron motion on
one molecule affecting the electron motion on the other through
electrical forces; these are the weakest interactions between
molecules
polarizability correct answer: the ability to be polarized. a larger
molecule or a longer straight molecule has MORE polarizability
Dipole correct answer: a polar molecule that has two poles, or
regions, with opposite charges
hydrogen bond forces correct answer: intermolecular force
between molecules -- attraction between two water molecules.
Instantaneous dipole correct answer: temporary dipole that
occurs for a brief moment in time when the electrons of an atom
,or molecule are distributed asymmetrically (through dispersion
forces)
Induced dipole correct answer: a dipole temporarily created in
an otherwise nonpolar molecule, induced by a neighboring
charge
Relation between atomic/molecular size and melting & boiling
points correct answer: melting and boiling points increase as
atomic/molecule size increases
Between polar and nonpolar molecules of the same mass, which
tends to have the higher boiling point? correct answer: Polar
molecules have dipole-dipole attractions, which are stronger
than nonpolar dispersion factors. So, polar molecules have
higher boiling points.
Hydrogen bonded to __, __, or __ atoms creates a highly polar
molecule correct answer: fluorine, oxygen, nitrogen
(OH, HF, NH groups are signifiers of high polarity and therefore
high boiling point)
these bonds are so strong that it leaves a "naked nucleus" which
increases the IMF force between molecules
Viscosity correct answer: a measure of a liquid's resistance to
flow.
cold = more viscous
, Cohesive forces correct answer: the result of the intermolecular
forces that attract identical molecules (attraction between water
molecules for example)
adhesive forces correct answer: result of intermolecular forces
between two different molecules (like the liquid molecules and
their container)
Surface tension correct answer: caused by uneven (cohesive)
forces at the surface of a liquid.
increased surface tension causes the surface of a liquid to act
like a membrane
capillary action correct answer: when a liquid flows within a
porous material due to the attraction of the liquid molecules to
the surface of the material and to other liquid molecules. The
adhesive forces between the liquid and the porous material,
combined with the cohesive forces within the liquid, may be
strong enough to move the liquid upward against gravity.
fusion correct answer: solid to liquid (endothermic)
vaporization correct answer: Liquid to gas (endothermic)
sublimation correct answer: solid to gas (endothermic)
condensation correct answer: Gas to liquid (exothermic)
freezing correct answer: liquid to solid (exothermic)
Complete Solutions
Intermolecular forces (IMFs) correct answer: the forces of
attraction between molecules of covalent compounds (weak)
Intramolecular forces correct answer: forces within molecules.
Forces caused by the attraction and repulsion of charged
particles (strong)
Dispersion forces correct answer: present in all molecules
attractions between molecules caused by the electron motion on
one molecule affecting the electron motion on the other through
electrical forces; these are the weakest interactions between
molecules
polarizability correct answer: the ability to be polarized. a larger
molecule or a longer straight molecule has MORE polarizability
Dipole correct answer: a polar molecule that has two poles, or
regions, with opposite charges
hydrogen bond forces correct answer: intermolecular force
between molecules -- attraction between two water molecules.
Instantaneous dipole correct answer: temporary dipole that
occurs for a brief moment in time when the electrons of an atom
,or molecule are distributed asymmetrically (through dispersion
forces)
Induced dipole correct answer: a dipole temporarily created in
an otherwise nonpolar molecule, induced by a neighboring
charge
Relation between atomic/molecular size and melting & boiling
points correct answer: melting and boiling points increase as
atomic/molecule size increases
Between polar and nonpolar molecules of the same mass, which
tends to have the higher boiling point? correct answer: Polar
molecules have dipole-dipole attractions, which are stronger
than nonpolar dispersion factors. So, polar molecules have
higher boiling points.
Hydrogen bonded to __, __, or __ atoms creates a highly polar
molecule correct answer: fluorine, oxygen, nitrogen
(OH, HF, NH groups are signifiers of high polarity and therefore
high boiling point)
these bonds are so strong that it leaves a "naked nucleus" which
increases the IMF force between molecules
Viscosity correct answer: a measure of a liquid's resistance to
flow.
cold = more viscous
, Cohesive forces correct answer: the result of the intermolecular
forces that attract identical molecules (attraction between water
molecules for example)
adhesive forces correct answer: result of intermolecular forces
between two different molecules (like the liquid molecules and
their container)
Surface tension correct answer: caused by uneven (cohesive)
forces at the surface of a liquid.
increased surface tension causes the surface of a liquid to act
like a membrane
capillary action correct answer: when a liquid flows within a
porous material due to the attraction of the liquid molecules to
the surface of the material and to other liquid molecules. The
adhesive forces between the liquid and the porous material,
combined with the cohesive forces within the liquid, may be
strong enough to move the liquid upward against gravity.
fusion correct answer: solid to liquid (endothermic)
vaporization correct answer: Liquid to gas (endothermic)
sublimation correct answer: solid to gas (endothermic)
condensation correct answer: Gas to liquid (exothermic)
freezing correct answer: liquid to solid (exothermic)
