Liquids, Solids, Changes of State, and Solutions Chem Review

Temperature

the measure of the average kinetic energy of the particles in a sample of matter

kinetic energy

the energy due to the motion of an object

volume

a measure of the amount of space occupied by a sample of matt

fluid

a substance that can flow and therefore take the shape of its container

density

the ratio of the amount of space occupied by a sample of matter

compressibility

the ability of a sample of matter to have its volume reduced under pressure

diffusion

the spontaneous mixing of two or more substances

surface tension

a force that tends to pull adjacent parts of a liquid’s surface together, thereby decreasing surface area to the smallest possible size

capillary action

the tendency of a liquid to rise up a narrow tube (CLOSELY RELATED TO SURFACE TENSION)

meniscus

the curve a liquid forms in such items as test tubes or graduated cylinders

viscosity

the resistance of a liquid to flow

crystal

a substance in which the particles are arranged in an orderly, geometric, repeating pattern

unit cell

simplest repeating unit of a crystal

crystal lattice

unit cells repeated over and over in a definite geometric arrangement (similar to bricks or blocks)

hydrate

a solid ionic compound containing water molecules incorporated into its solid crystal structure

anhydrous salt

an ionic compound that remains after the water has been removed from a hydrate (usually by heating)

vapor

gas phase of a substance that is normally a solid or liquid at room temperature

universe

everything

system

the part of the universe on which attention is focused

surroundings

everything in the universe except the system (usually only concerned with the surroundings near the system)

closed system

system in which matter CANNOT enter and leave the system (but energy can enter and leave)

open system

system in which matter CAN enter and leave the system (energy also can enter and leave)

vaporization

a general term for the process by which a liquid changes to a gas

evaporation

the process by which particles escape from the surface of a non-boiling liquid and enter the gas state (evaporation is a type of vaporization)

melting

solid → liquid (ice → water)

freezing

liquid → solid (water → ice)

vaporization

liquid → gas (liquid bromine → bromine vapor)

condensation

gas → liquid (water vapor → water)

sublimation

solid → gas (dry ice → CO2 gas)

deposition

gas → solid (iodine vapor → solid iodine)

volatile liquid

a liquid that will evaporate readily

nonvolatile liquid

a liquid that will evaporate slowly

equilibrium

a dynamic condition in which two opposing physical or chemical changes occur at equal rates in a given closed system

equilibrium vapor pressure

the pressure exerted by a vapor in equilibrium with its corresponding liquid at a given temperature

Le Chatelier’s Principle

when a system at equilibrium is disturbed by application of a stress, it attains a new equilibrium position that minimizes the stress

boiling

the conversation of a liquid to a vapor within the liquid as well as at its surface

boiling point

the temperature at which the equilibrium vapor pressure of a liquid is equal to the external pressure on the liquid (often atmospheric pressure)

normal boiling point

the temperature at which the equilibrium vapor pressure of a liquid is exactly 1 atm

phase diagram

way of representing the state of matter of a substance in a closed system as a function of temperature and pressure

triple point

indicates the temperature and pressure conditions at which the solid, liquid, and gas (vapor) of a substance can coexist at equilibrium

critical point

indicates the critical temperature and critical pressure of a substance

critical temperature

the temperature above which a substance CANNOT exist in the liquid state no matter how high the pressure exerted

critical pressure

the lowest pressure at which the substance can exist as a liquid at the critical temperature

mixture

matter that:

• can be separated into two or more pure substances by physical change

• contains two or more pure substances, each of which retains its own identity and properties

• has a variable composition

suspension

a heterogeneous mixture that separates on standing

colloid

a heterogeneous mixture that does NOT separate on standing

solution

a homogeneous mixture

Tyndall effect

visible pattern caused by the reflection of light from dispersed particles in a colloid (or from suspended particles in an “unsettles suspension”)

sol

solid dispersed in gas

gel

solid network extending throughout liquid

liquid emulsion

liquid dispersed in liquid (ex. mayonnaise)

foam

gas dispersed in liquid (ex. whipped cream)

aerosols

• smoke - solid dispersed in gas

• fog - liquid dispersed in gas

• smog - solid and liquid dispersed in gas

solid emulsion

liquid dispersed in solid (ex. cheese)

brownian motion

the random continuous motion of colloidal particles

solvent

the substance that does the dissolving in a solution (typically present in the higher amount)

solute

the substance being dissolved in a solution (typically present in the lower amount)

aqueous solution

a solution in which water is the solvent

alloy

a solid solution in which the atoms of two or more metals are uniformly mixed

solution concentration

a measure of the amount of solute in a given amount of solvent or solutuon

molarity

the number of moles of solute per one liter of solution