Question 1

Which property of water allows insects such as water striders to walk on its surface without sinking?

Accepted Answer

Surface tension

Question 2

A liquid is observed to have a high resistance to flow and forms droplets with a minimized surface area. Which intermolecular force is primarily responsible for these properties?

Accepted Answer

Hydrogen bonding

Question 3

Which of the following statements best explains why ice floats on water?

Accepted Answer

Ice is less dense than liquid water due to expansion upon freezing

Question 4

Calculate the amount of heat (in kJ) required to vaporize 50.0 g of water at its boiling point. The heat of vaporization of water at 100°C is $$40.7\ 	ext{kJ/mol}$$ and the molar mass of water is $$18.02\ 	ext{g/mol}.$$

Accepted Answer

$$113\ 	ext{kJ}$$

Question 5

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

Accepted Answer

Dispersion force

Question 6

A sample of dry ice (solid CO$$_2) is $$left on a table and gradually disappears without forming a liquid. What process is occurring?

Accepted Answer

Sublimation

Question 7

Which of the following best describes the difference between solids and liquids at the molecular level?

Accepted Answer

Solids have molecules fixed in place, while liquids have molecules free to move around each other

Question 8

Which intermolecular force is responsible for the high boiling point of water compared to other molecules of similar molar mass?

Accepted Answer

Hydrogen bonding

Question 9

A 20.0 g ice cube melts at 0°C. How much heat (in kJ) is absorbed during the melting? The heat of fusion for water is $$6.02\ 	ext{kJ/mol}$$ and the molar mass of water is $$18.02\ 	ext{g/mol}.$$

Accepted Answer

$$6.68\ 	ext{kJ}$$

Question 10

Which of the following is NOT a property of gases?

Accepted Answer

Definite volume

Question 11

Which intermolecular force is strongest among the following?

Accepted Answer

Ion-dipole force

Question 12

Why does sweat cool the human body?

Accepted Answer

Evaporation of sweat is endothermic and absorbs heat from the skin

Question 13

Which of the following statements about melting and freezing is correct?

Accepted Answer

Melting is endothermic and freezing is exothermic

Question 14

Which type of solid is held together by actual ionic bonds and tends to have high melting points?

Accepted Answer

Ionic solid

Question 15

Which of the following best explains why oil and water do not mix?

Accepted Answer

Oil is nonpolar and water is polar, so they are not miscible

Question 16

Which process is exothermic and releases heat to the surroundings?

Accepted Answer

Condensation

Question 17

Which of the following is a molecular solid held together primarily by hydrogen bonds?

Accepted Answer

Ice (solid H$$_2O)$$

Question 18

Which property of water is essential for aquatic life during winter?

Accepted Answer

Ice floats and insulates the water below, preventing lakes from freezing solid

Question 19

Which intermolecular force is responsible for the specific pairing of DNA bases (A with T, C with G)?

Accepted Answer

Hydrogen bonding

Question 20

Which of the following statements about vapor pressure is correct?

Accepted Answer

Vapor pressure increases with increasing temperature and decreasing strength of intermolecular forces

Liquids, Solids, and Intermolecular Forces: Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard