Chemistry 1 Practice Test Short Answered Questions

The bulk properties of liquids are determined by the

intermolecular forces

The molecules in a liquid are in constant motion, but since the mean free path is very short, their rate of __________ is much slower than in gases.

diffusion

In a phase diagram, the point where solid, liquids, and gases all coexist is the __________

triple point

Any time a material goes from a more ordered state to a less ordered state, the process is

endothermic

If the molecules have a(n) __________, the molecules will tend to align themselves with the positive end of one molecule near the negative end of the next.

dipole moment

Vapor pressure is a(n) __________ brought about by evaporation and condensation occurring at equal rates.

dynamic equilibrium

The freezing point of water __________ as the pressure is increased.

decreases

The molecules of a liquid are packed close together, so the __________ of a liquid is much higher than a gas.

density

The __________ is the highest temperature at which a material can exist as a liquid.

critical temperature

The __________ of a liquid is the temperature where the vapor pressure equals 1 atmosphere

normal boiling point

When a cooling curve is plotted, there is often a drop in temperature below the melting point of the material, before it starts to solidify. This initial dip is an indicator of

supercooling

Water is unusual because the __________ of solid water is less than liquid water near its melting point.

density

__________ is the resistance of a liquid to flow

Viscosity

In a(n) __________ phase, the molecules are pointed in the same direction but can slide past one another

nematic

When we are heating a liquid in the laboratory, we often add a boiling chip to the flask in order to prevent formation of a(n)__________, which might bump.

superheated liquid

Bromine is a liquid and chlorine is a gas at room temperature because the strength of __________ depends on the number of electrons and the shape of the molecule.

London dispersion forces

__________ allows insects to walk on the surface of a liquid and causes beads of liquid to form.

Surface tension

Nonpolar molecules interact with each other through __________.

London dispersion forces

In liquid acetone, (CH3)2C=O), __________ are the strongest intermolecular force.

dipole-dipole attractions

When dry ice warms up, it changes directly from a solid to a gas in a process known as __________.

sublimation

__________ are made from the combination of a small spherical anion with a large asymmetrical cation and have melting points below room temperature

Ionic liquids

Molecules in a(n) __________ liquid are held together by strong intermolecular forces, which results in a low vapor pressure.

nonvolatile

A liquid where the molecules are equally disordered in all directions is __________.

isotropic

When a material is heated above its critical temperature at a pressure above its critical pressure, the phase of the material is a(n)__________.

supercritical fluid

Liquid crystals have unusual optical properties because they can __________ with an electric field and change their orientation

interact

For compounds with hydrogen atoms bonded to nitrogen, oxygen, or fluorine, __________ are an extreme form of dipole-dipole interaction due to the large dipole moment and short distances.

hydrogen bonds

Plants rely on __________ to transport water from the roots to the leaves.

capillary action

Two liquids that form a solution for all compositions are __________ with each other.

miscible

__________ describes the solubility of a gas in a solvent based on its partial pressure.

Henry's law

If the enthalpy of solution is positive and still a solution forms, the __________ of solution must also be positive.

entropy

An anion and cation that exist together for short periods of time are __________.

ion pairs

__________ is the principle that is used when salt is spread on the roads to melt snow and ice.

Freezing-point depression

A(n) __________ solution will spontaneously crystallize if a seed crystal is added.

supersaturated

__________ occurs when water is returned to a river or lake at a higher temperature than when it was removed

Thermal pollution

The solubility of gases __________ as the temperature is increased in contrast to the solubility of most solids.

decreases

The energy to overcome the intermolecular interactions in a solute and form a solution comes from the __________ of the solute particles.

solvation

__________ are properties that depend only on the number of solute particles present in solution.

Colligative properties

A(n) __________ is a solution whose properties can be explained in terms of a simple model.

ideal solution

The __________ allows the number of particles formed when a solute dissolves in a solvent to be accounted for in determining colligative properties.

van't Hoff factor

The entropy of solution is positive because the solution is more __________ than pure solvent and solute

disordered

Components of a mixture can be purified by __________ because of differences in their solubilities in a solvent at different temperatures.

fractional crystallization

The __________ of water is one of the highest known, which explains why water will dissolve many ionic compounds.

dielectric constant

The disease sickle-cell anemia is caused by the replacement of one hydrophilic amino acid by a(n) __________ amino acid.

hydrophobic

Solutions of metals in liquid mercury are __________ and are usually solids and can be used in gold mining or dentistry.

amalgams

A(n) __________ is essentially a mixture of phospholipid molecules that form a bilayer and act to separate components

cell membrane

The __________ is the scattering of a beam of light by colloidal particles

Tyndall effect

A class of compounds called __________ was developed in order to dissolve ionic compounds in nonpolar solvents

crown ethers

Smoke and fog are examples of __________, where a liquid or solid is dispersed in a gas

aerosols

A(n) __________ is a mixture that will separate on standing and may be filtered.

suspension

When a nonvolatile solute is dissolved in a solvent, both the __________ and the freezing point of the solution are lowered.

vapor pressure

__________ allows the vapor pressure of a solution to be predicted based on the mole fraction of each component.

Raoult's law

The __________ of a solution is the number of moles of solute per kilogram of solvent.

molality

__________ uses pressure to force solvent molecules through a semipermeable membrane to purify the solvent

Reverse osmosis

Detergents and soaps spontaneously form __________ in order to minimize interactions of the nonpolar tails with water.

micelles

A molecule that contains a number of polar functional groups would be classified as __________.

hydrophilic