Questions With Complete Solutions
A hydrogen bond is characterized by
A. the attraction of temporary dipoles produced by the random
asymmetries in electron motion
B. the electrostatic attraction between the permanent dipoles in
any polar molecule
C. the highly concentrated partial charge between an H atom and
F, O, or N atoms
D. the covalent sharing of electrons between two atoms in a
molecule correct answer: C. the highly concentrated partial
charge between an H atom and F, O, or N atoms
(Ref: Week 1 Quiz)
A. LDF's
B. Dipole-Dipole
D. Covalent Bond
Which of the following will have the strongest dipole-dipole
attractions?
,A. NCl3
B. CCl4
C. BCl3
D. Cl2 correct answer: A. NCl3
(Ref: Week 1 Quiz)
Asymmetrical - Usually have a higher dipole moment
Why not BCl3? Because Nitrogen is more electronegative than
Boron.
A cohesive force
A. is the result of the intermolecular forces that attract identical
molecules
B. is the result of the intermolecular forces that attract different
molecules together
C. is the result of covalent interactions between atoms in a
molecule
D. is always stronger than an adhesive force correct answer: A.
is the result of the intermolecular forces that attract identical
molecules
(Ref: Week 1 Quiz)
, Easy way to remember. Co = mutual so cohesive is identical
molecules.
ΔHvap is
A. the energy change when a substance changes from the liquid
phase to the gas phase
B. the energy change when a substance changes from the solid
phase to the liquid phase
C. the energy change when a substance changes from the liquid
phase to the solid phase
D. the energy change when a substance changes from the solid
phase directly to the gas phase correct answer: A. the energy
change when a substance changes from the liquid phase to the
gas phase
(Ref: Week 1 Quiz)
Liquid → Gas (Vaporization)
Ex: Boiling
A liquid in a tube will form a convex meniscus when
A. the adhesive forces are stronger than the cohesive forces
B. the cohesive forces are stronger than the adhesive forces