Chp. 12: Liquids, Solids, & Intermolecular Forces

viscosity is:

the resistance of a liquid to flow

the rate of vaporization increases with:

surface area, temperature, weak intermolecular forces

liquids that evaporate easily are termed:

volatile

liquids that do not vaporize easily are termed:

nonvolatile

evaporation occurs because:

molecules on the surface of a liquid are held less tightly than those in the interior, so the most energetic among them can break away into a gaseous state

vapor pressure increases with:

temperature, weak intermolecular forces

During boiling, the temperature remains at ______ until all the liquid is evaporated.

100 degrees Celsius

Evaporation, in terms of energy, is:

endothermic (absorption)

Evaporation is endothermic because when liquid is converted into a gas, it:

absorbs heat energy that is required to break molecules away from the rest of the liquid.

Condensation, in terms of energy, is:

exothermic

The amount of heat required to vaporize (cause to evaporate) 1 mol of liquid is the:

heat of vaporization

At the melting point, atoms and molecules have enough thermal energy to overcome:

the intermolecular forces that hold them at their stationary points, and the solid turns into a liquid.

When ice melts, water molecules break free from the solid structure and become liquid. As long as ice and water are both present:

the temperature will be 0 degrees Celsius.

The amount of heat required to melt 1 mol of a solid is the:

heat of fusion

At temperatures below 0 degrees Celsius, ice will:

slowly sublime

Types of Intermolecular Forces: dispersion, dipole-dipole, and:

hydrogen bonding

Types of Intermolecular Forces: _______, dipole-dipole, hydrogen bonding

dispersion

Types of Intermolecular Forces: dispersion, _______, hydrogen bonding

dipole-dipole

Dipole-dipole force exists in:

all polar molecules

Polar molecules have permanent dipoles that:

interact with permanent dipoles of neighboring molecules (think H₂O!)

dipole-dipole force

the positive end of one permanent dipole is attracted to the negative end of another

miscibility: a liquid’s ability to mix with another liquid…

without separating into two phases

Polar molecules containing hydrogen atoms bonded directly to fluorine, oxygen, or nitrogen exhibit:

an additional intermolecular force called a hydrogen bond

A hydrogen bond is a sort of ____ dipole-dipole force.

super

crystalline solids can be:

molecular, ionic, or atomic

example of a molecular solid

ice (solid H₂O) and dry ice (solid CO₂)

example of an ionic solid

NaCl

example of an atomic solid

Au

Ionic solids tend to have ______ than molecular solids.

much higher melting points

vapor pressure is independent of surface area because:

surface area affects condensation and evaporation rates equally

A concave meniscus is evidence that ______ in a liquid.

adhesion is greater than cohesion

A convex meniscus is evidence that _______ in a liquid.

cohesion is greater than adhesion

the opposite of sublimation, or the direct process by which a gas becomes a solid, is:

deposition