Chem Vocab pt.1

Energy needed to get a reaction started

Amphoteric

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

Avogadro's number

6.02 x 10^23, the number of atoms or molecules in 1 mol

Buffer

compound that prevents sharp, sudden changes in pH

Calorimetry

The precise measurement of heat flow out of a system for chemical and physical processes

Catalyst

substance that speeds up the rate of a chemical reaction

chemical change

A change in matter that produces one or more new substances

Chromatography

A laboratory technique used to separate mixtures of molecules

covalent bond

a bond formed when atoms share one or more pairs of electrons

Dilution

Adding water to a solution in order to decrease the concentration

dipole moment

a property of a molecule whose charge distribution can be represented by a center of positive charge and a center of negative charge

Distillation

the action of purifying a liquid by a process of heating and cooling.

Electronegativity

the ability of an atom to attract electrons when the atom is in a compound

Endothermic

Absorbs heat

Enthalpy

The heat content of a system at constant pressure

Entropy

A measure of disorder or randomness.

equivalence point

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

excess reactant

the reactant that is not completely used up in a chemical reaction

Exothermic

Releases heat

Frequency

the number of complete wavelengths that pass a point in a given time

gravimetric analysis

an analytical technique based on the measurement of mass

heterogeneous mixture

A mixture in which different materials can be distinguished easily

homogeneous mixture

a mixture in which the composition is uniform throughout

Hydrophillic

Attracted to water

Hydrophobic

Water fearing

Immiscible

liquids that are not soluble in each other

ion

A charged atom

ionazation energy

the energy required to remove an electron from an atom

isotope

Atoms of the same element that have different numbers of neutrons

Algia