Chemistry Final Vocab

mole

Avogadro's number

number of representative particles in a mole, 6.02 X 10^23

molar

a term expressing molarity, the number of moles of solute per liters of solution

percent composition

the percent by mass of each element in a compound

empirical formula

a chemical formula showing the ratio of elements in a compound rather than the total number of atoms

molecular formula

A chemical formula that shows the number and kinds of atoms in a molecule, but not the arrangement of the atoms.

hydrate

A compound that has a specific number of water molecules bound to its atoms

Stoicheometry

the relationship between the relative quantities of substances taking part in a reaction or forming a compound, typically a ratio of whole integers.

mole ratio

a conversion factor that relates the amounts in moles of any two substances involved in a chemical reaction

limiting reactant

the substance that controls the quantity of product that can form in a chemical reaction

excess reactant

the substance that is not used up completely in a reaction

theoretical yield

the maximum amount of product that can be produced from a given amount of reactant

actual yield

the measured amount of a product obtained from a reaction

percent yield

actual yield/theoretical yield x 100

Kinetic Molecular Theory

based on the idea that particles of matter are always in motion

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration.

elastic collision

A collision in which colliding objects rebound without lasting deformation or the generation of heat.

Temperature

A measure of how hot or cold something is.

Grahm's Law of Effusion

the rates of effustion of gases at the same temperature and pressure are inversely proportional to the square roots of their molar masses Rate of effusion of A / B \= √Mb / √Ma

pressure

Force per unit area.

barometer

An instrument that measures atmospheric pressure

Pascal

SI unit of pressure

atmosphere

A mixture of gases that surrounds a planet or moon.

Dalton's Law of Partial Pressures

states that the total pressure of a mixture of gases is equal to the sum of the pressures of all the gases in the mixture

dispersion forces

attractions between molecules caused by the electron motion on one molecule affecting the electron motion on the other through electrical forces; these are the weakest interactions between molecules

dipole-dipole forces

attractions between oppositely charged regions of polar molecules

hydrogen bond

weak attraction between a hydrogen atom and another atom

Viscosity

A liquid's resistance to flowing

surface tension

the force that acts on the surface of a liquid and that tends to minimize the area of the surface

Surfactant

chemical produced in the lungs to maintain the surface tension of the alveoli and keep them from collapsing

crystalline solid

A solid that is made up of crystals in which particles are arranged in a regular, repeating pattern

unit cell

the smallest group of particles within a crystal that retains the geometric shape of the crystal

Allotrope

One of two or more different molecular forms of an element in the same physical state

amorphous solid

A solid made up of particles that are not arranged in a regular pattern

melting point

The temperature at which a solid becomes a liquid

Vaporization

The change of state from a liquid to a gas

Evaporation

The change of a substance from a liquid to a gas

vapor pressure

the pressure exerted by a vapor over a liquid

boiling point

The temperature at which a liquid changes to a gas

freezing point

The temperature at which a liquid changes into a solid

Condensation

Gas to liquid

Deposition

Process in which sediment is laid down in new locations.

phase diagram

A graph of pressure versus temperature that shows the conditions under which the phases of a substance exist

triple point

the point on a phase diagram at which the three states of matter: gas, liquid, and solid

Boyle's law

P1V1\=P2V2

absolute zero

the point where no more heat can be removed from a system, according to the absolute or thermodynamic temperature scale

Charles's law

V1/T1\=V2/T2

Gay-Lussac's Law

P1/V2\=P2/V2

combined gas law

P1V1/T1 \= P2V2/T2

Avogadro's principle

V1/n1 \= V2/n2

standard pressure and temperature (STP)

refers to the nominal conditions in the atmosphere at sea level.

ideal gas constant

8.314J/K⋅mo

ideal gas law

the equation of state of a hypothetical ideal gas

Suspension

A mixture in which particles can be seen and easily separated by settling or filtration

Colloid

A mixture containing small, undissolved particles that do not settle out.

Brownian motion

the chaotic movement of colloidal particles, caused by collision with particles of the solvent in which they are dispersed

Tyndell Effect

the scattering of light by colloid particles

soluble

capable of being dissolved

Miscible

Describes two liquids that are soluble in each other

Insoluble

impossible to solve or fix; unable to be dissolved

Immiscible

liquids that are not soluble in each other

Concentration

A measurement of how much solute exists within a certain volume of solvent

Molarity

the number of moles of solute per liter of solution

Molality

moles of solute/kg of solvent

mole fraction

The ratio of the moles of solute in solution to the total number of moles of both solvent and solute

Solvation

The process of surrounding solute particles with solvent particles to form a solution

heat of solution

the overall energy change that occurs during the solution formation process

unsaturated solution

A solution that contains less solute than a saturated solution does and that is able to dissolve additional solute

saturated solution

a solution that contains the maximum amount of dissolved solute

supersaturated solution

contains more dissolved solute than a saturated solution at the same temperature

Henry's Law

the solubility of a gas in a liquid is directly proportional to the partial pressure of that gas on the surface of the liquid

colligative properties

properties of a solution that depend only on the number of particles dissolved in it, not the properties of the particles themselves. The main ones are boiling point elevation and freezing point depression.

vapor pressure lowering

The lowering of vapor pressure of a solvent by the addition of a nonvolatile solute to the solvent.

boiling point elevation

the difference in temperature between the boiling point of a solution and the boiling point of the pure solvent

Osmosis

Diffusion of water through a selectively permeable membrane

osmotic pressure

pressure that must be applied to prevent osmotic movement across a selectively permeable membrane

acidic solution

contains more hydrogen ions than hydroxide ions

basic solution

contains more hydroxide ions than hydrogen ions

Arrhenius model

states that an acid is a substance that contains hydrogen and ionizes to produce hydrogen ions in aqueous solution

Bronsted-Lowry acid

a molecule or ion that is a proton donor

conjugate acid

the particle formed when a base gains a hydrogen ion

conjugate base

the particle that remains when an acid has donated a hydrogen ion

conjugate acid-base pair

consists of two substances related to each other by the donating and accepting of a single hydrogen ion

Amphoteric

a substance that can act as both an acid and a base

Lewis model

a Lewis acid is an electron-pair acceptor and a Lewis base is an electron-pair donor

strong acid

an acid that ionizes completely in aqueous solution

weak acid

an acid that is only slightly ionized in aqueous solution

acid ionization constant

the value of the equilibrium constant expression for the ionization of a weak acid

stong base

a base that completely ionizes in water

weak base

A base that does not dissociate completely into ions in solution.

base ionization constant

the value of the equilibrium constant expression for the ionization of a base

ion product constant for water

the value of the equilibrium constant expression for the self-ionization of water

pH\=

-log[H+]

pOH

-log[OH-]

nuetralization reaction

acids and bases react to form water and a salt

salt

An ionic compound made from the neutralization of an acid with a base.

Titration

a measured amount of a solution of unknown concentration is added to a known volume of a second solution until the reaction between them is just complete

equivalence point

the point at which the two solutions used in a titration are present in chemically equivalent amounts

acid-base indicator

a chemical dye whose color is affected by acidic and basic solutions

end point

the point in a titration at which an indicator changes color