$q = mass \times C_s \times \Delta T$

Question 1

Which of the following statements best explains why geckos can climb smooth surfaces?

Accepted Answer

Geckos have millions of tiny hairs that allow unusually close contact, maximizing intermolecular attractive forces.

Question 2

Which phase of water has the lowest density, and why is this significant for life on Earth?

Accepted Answer

Ice; it floats on liquid water, insulating aquatic life in cold climates.

Question 3

Which type of molecular motion is present in solids but not in gases?

Accepted Answer

Vibrational freedom

Question 4

According to the kinetic-molecular theory, what two factors determine the state of a material?

Accepted Answer

The amount of kinetic energy and the strength of intermolecular attractions

Question 5

Which equation correctly relates the average kinetic energy of particles to temperature?

Accepted Answer

$KE_{avg} = 1.5kT$

Question 6

Which intermolecular force is present in all molecules and atoms, regardless of polarity?

Accepted Answer

Dispersion forces (London forces)

Question 7

Why do larger molecules generally have higher boiling points than smaller ones?

Accepted Answer

They have more electrons, leading to increased polarizability and stronger dispersion forces.

Question 8

Which of the following molecules would have the highest boiling point?

Accepted Answer

n-Propanol ($C_3H_7OH$)

Question 9

Which statement best describes hydrogen bonding?

Accepted Answer

It occurs when hydrogen is bonded to a highly electronegative atom, exposing the proton and creating a strong attraction.

Question 10

Which factor will increase the surface tension of a liquid?

Accepted Answer

Increasing the strength of intermolecular forces

Question 11

A liquid is placed in a thin glass tube. The meniscus is concave. What does this indicate about the forces involved?

Accepted Answer

Adhesive forces are stronger than cohesive forces.

Question 12

Which process is endothermic and requires energy input to occur?

Accepted Answer

Vaporization

Question 13

What is the heat of vaporization ($\Delta H_{vap}$)?

Accepted Answer

The amount of heat required to vaporize one mole of a liquid

Question 14

Which equation would you use to calculate the energy required to heat a substance through a temperature change?

Accepted Answer

$q = mass 	imes C_s 	imes \Delta T$

Question 15

What is the main factor that determines the solubility of ionic compounds in water?

Accepted Answer

The strength of ion-dipole attractions

Question 16

Which intermolecular force is the strongest in a pure substance?

Accepted Answer

Hydrogen bonds

Question 17

Which of the following best describes a supercritical fluid?

Accepted Answer

A state where the liquid and vapor phases are indistinguishable and co-mingle

Question 18

What is the triple point in a phase diagram?

Accepted Answer

The temperature and pressure where all three phases (solid, liquid, gas) exist simultaneously

Question 19

Which of the following statements about water is true?

Accepted Answer

Water expands when it freezes, making ice less dense than liquid water.

Question 20

Which of the following would increase the vapor pressure of a liquid?

Accepted Answer

Decreasing the strength of intermolecular forces

Liquids, Solids, and Intermolecular Forces – Chapter 12 Study Notes

Study Guide - Practice Questions