Chemistry - A Molecular Science

Glossary

Hybridization

is the process by which hybrid orbitals

are produced from atomic orbitals.

A

hydrate

is a compound with a characteristic number

of water molecules associated with it.

Hydration

is the process in which a solute particle

interacts with the surrounding water molecules.

A

hydrocarbon

is a compound that contains only

carbon and hydrogen.

Hydrogenation

is the addition of hydrogen to a

compound.

The

hydrogen bond

is an especially strong dipolar

interaction that occurs in compounds containing a hydrogen atom attached to N, O, or F.

The

hydronium ion (H

O 3

1+)

is the conjugate acid of

water. Therefore, it is the strongest acid that can be present in aqueous solutions.

A

hydrophilic

molecule interacts well with water.

A

hydrophobic

molecule is excluded from water

because it does not inte

ract well with water.

The

hydrophobic effect

is the tendency of water to

exclude hydrophobic molecu

les by establishing an

ice-like structure

around them.

A

hypothesis

is a proposed explanation of an

observation. If a hypothesis proves successful in explaining many other experiments, it becomes a theory, but if it fails to explain a test, it is discarded or modified.

I

An

ideal gas

is a hypothetical gas composed of

molecules that do not interact with one another.

The

ideal gas law

is the relationship between the

pressure (P), volume (V), temperature (T) and number of moles (n) of an ideal gas. PV = nRT.

Ideal gases obey the ideal gas law at all T and P, while real gases deviate at high P and low T.

An

indicator

is a compound that changes color within

a small pH range. The pH at which the indicator changes color is called the end point.

An

induced dipole

is a molecular dipole in one

molecule caused by th

e asymmetric charge

distribution in a neighboring molecule.

The

instantaneous rate

of a reaction is the rate at a

specified time. It is equal to the slope of the concentration

vs.

time plot at the specified time.

An

insulator

is a substance that does not conduct

electricity at reasonable

temperatures because its

band gap is too large.

An

integrated rate law

expresses the concentration of

a reactant as a function of time.

An

intensive property

is independent of sample size.

Color and density are intensive properties.

An

intermediate

in a chemical reaction is a substance

that is formed and then

consumed in the reaction.

Intermediates do not appear in the net chemical equation for the reaction.

Intermolecular

interactions

are between different

molecules. Dipolar and dispersion forces are intermolecular interactions.

Intramolecular interactions

are within a molecule.

Chemical bonds are intramolecular interactions.

An

ion

is a charged chemical species.

The

ion product (Q

) is the reaction quotient for the ip

reaction in which a solid dissolves as its ions in solution. Q

= Kip

at equilibrium. sp

The

ion product constant of water (K

) is the w

equilibrium constant for the reaction 2H

O 2

U

H^3

1+O

+ OH

1-. K

= [Hw

O 3

1+][OH

1-], which has a

value of 1.0x10

-14

at 25

oC.

An

ionic bond

is an electrostatic (Coulombic) force

between oppositely charged ions.

The

ionic radius

of an ion is determined from the

distances between it and ad

jacent ions in an ionic

crystal. The distance between the two adjacent ions equals the sum of their ionic radii.

The

ionization energy

is the energy required to

remove an electron from an

atom or molecule.

Ionizing radiation

is high energy radiation that can

remove electrons from a substance. X-rays are ionizing radiation.

Two substances are

isoelectronic

if they have the same

number of electrons.

Isomers

are different molecules with the same formula.

Isotopes

are atoms with the same atomic number but

different mass numbers,

i.e

., isotopes have the same

number of protons but different numbers of neutrons.

J

The

joule (J)

is the SI unit of energy.

1 J = 1 kg

.m

2 .s

-2^

K

Kaolinite clays

are composed of silicate and aluminate

layers (aluminosilicates). They are the main component of china clay.

The

kelvin (K)

is the SI unit of temperature. K =

oC +

273.15.

Kinetics

is the study of reaction rates and mechanisms.

Kinetic energy

(KE=

1 /^2

mv

2 ) is energy of motion.

Anything in motion has the capacity to do work on another object by simply colliding with it.

© by

North

Carolina

State

University