U3E2 Review

Which of the following statements are true and supported by the Kinetic Molecular Theory?

I. Ideal gas behavior is better achieved at high pressure and high temperature

II. The kinetic energy of a molecule is directly proportional to its absolute temperature

III. As the temperature of a gas increases, the system pressure decreases

• II

• I

• I, II and III

• I and II

Real gases behave most nearly like ideal gases at .

• high pressures and low molar masses

• low temperatures and high pressures

• high temperatures and low pressures
• high temperatures and high pressures

Rank the following gases in order of increasing non-ideality due to intermolecular forces.

CF4 He HCl N2

• HCl < CF₄ < N₂ < He

• He < N₂ < CF₄ < HCl

• He < N₂ < HCl < CF₄

• CF₄ < HCl < N₂ < He

Consider the two water molecules. Which statement is correct?

• The covalent bond A is weaker than the hydrogen bond B.

• The hydrogen bond A is stronger than the covalent bond B.

• The hydrogen bond A is weaker than the covalent bond B.

• The covalent bond A is stronger than the hydrogen bond B.

What are all the intermolecular forces that are responsible for the existence of dry ice, CO2(s)?

• dipole-dipole and dispersion forces

• dispersion forces

• dipole-dipole, dispersion forces, and hydrogen bonding

• dipole-dipole and ion-ion

Which of the following statements about dispersion forces is NOT correct?

• Dispersion Forces are also called London forces.

• Dispersion Forces decrease in strength with increasing molecular mass.

• Dispersion Forces are temporary rather than permanent dipole-dipole interactions.

• Dispersion Forces are the only forces between non-polar molecules.

In which of these compounds would you find ONLY dispersion forces existing between the molecules?

I. CCl4

II. PH3

III. HBr

• I only

• I and III only

• II only

• II and III only

Which of the following responses include compounds that exhibit hydrogen bonding as their most significant intermolecular force?

CH4, AsH3, CH3NH2, H2S, HF

• AsH₃, H₂S

• CH₃NH₂, HF

• CH₄, AsH₃, H₂S

• HF, H₂S

Which of the following is NOT a characteristic of a hydrogen bond?

• It is the covalent bond between hydrogen and very electronegative elements like F.

• It is stronger than other dipole-dipole interactions.

• It is responsible for the unusual physical properties of water.

• It is weaker than a triple bond.

For which of the molecules will dipole-dipole interactions be important?

I. Co2

II. O3

III> So2

IV. O2

• I only

• I and III only

• II and III only

• IV only