Unit 4: Liquids and Solids

31. The temperature at which a liquid turns into a gas is called:

a) Freezing point
b) Melting point
c) Boiling point
d) Condensation point
Answer: c) Boiling point

32. The intermolecular force that causes water to have a high boiling point compared to other molecules of similar size is:

a) London dispersion forces
b) Dipole-dipole interactions
c) Hydrogen bonding
d) Ionic bonding
Answer: c) Hydrogen bonding

33. A substance that can form both liquid and solid phases in equilibrium is called a:

a) Amorphous solid
b) Glass
c) Crystalline solid
d) Polymer
Answer: b) Glass

34. The process where liquid molecules leave the surface and enter the gas phase is known as:

a) Boiling
b) Evaporation
c) Sublimation
d) Condensation
Answer: b) Evaporation

35. In which type of solid are atoms bonded by covalent bonds forming a network throughout the solid?

a) Ionic solid
b) Metallic solid
c) Covalent network solid
d) Molecular solid
Answer: c) Covalent network solid

36. The pressure exerted by a vapor in equilibrium with its liquid is called:

a) Vapor pressure
b) Atmospheric pressure
c) Partial pressure
d) Osmotic pressure
Answer: a) Vapor pressure

37. The ability of a liquid to form hydrogen bonds with itself is responsible for its:

a) High density
b) High viscosity
c) High surface tension
d) Low vapor pressure
Answer: c) High surface tension

38. Which of the following is a characteristic property of an amorphous solid?

a) Long-range order
b) Repeating unit cells
c) Lack of a well-defined melting point
d) Strong covalent bonds throughout
Answer: c) Lack of a well-defined melting point

39. Which of the following is true for ionic solids?

a) They have high melting points and conduct electricity in the solid state
b) They have low melting points and are typically non-conductive
c) They are formed by covalent bonds and have low melting points
d) They are formed by metallic bonds and are malleable
Answer: a) They have high melting points and conduct electricity in the solid state

40. The temperature and pressure at which all three phases (solid, liquid, and gas) of a substance coexist in equilibrium is known as:

a) Freezing point
b) Boiling point
c) Triple point
d) Critical point
Answer: c) Triple point