Glossary of Chemical Terms - C

C

calorie

The amount of energy needed to raise the temperature of 1 gram of water by 1 degree Celsius.

calorimeter

Any one of a number of devices used for measuring the heat content.

carbocyclic

Being or having an organic ring of carbon atoms.

carbohydrate

An organic compound with the general formula C_x(H₂O)_y.

carcinogen

A cancer-causing agent.

catalysis

A process in which a catalyst increases the speed of a chemical reaction.

catalyst

A substance which increases the rate of a chemical reaction, but itself remains unchanged at the end of the reaction.

cathode

A negative electrode.It is the electrode from which current leaves an electrolytic cell.

cation

A positively charged ion.

caustic

Corrosive; able to eat away or destroy by chemical action.

chelated

Combined with a metal to form a chelate ring, in which a metal ion is held by coordinate bonds.

chiral

Relating to a molecule that cannot be superimposed on its mirror image.

chlorofluorocarbons

Synthetic compounds containing carbon, chlorine, fluorine, and sometimes hydrogen that are used in refrigerants, propellants, the manufacture of foams, and cleaning solvents.

chlorophyll

The catalytic substance in photosynthesis that contains a Mg²+ ion inthe center of a specialized ring structure known as a porphyrin.Porphyrins have a central portion containing nitrogen atoms that canattach to a metal ion.

chromatography

Any process for separating materials using two phases, one stationary, and one moving.One example: gas chromatography (gas as moving phase, solid as stationary phase).

colloid

A substance consisting of particles dispersed throughout another substance.

combustion

Rapid oxidation (burning) accompanied by the release of heat.

composting

The controlled biological decomposition of organic solid wastes under aerobic (in the presence of oxygen) conditions.Organic materials are transformed into soil enhancers such as humus and mulch.

condensation

The process of vapor molecules forming a liquid.

couples

A half-reaction which explicitly shows electron transfer

covalent bond

Bonds that hold atoms together by the sharing of electrons.

covalent radius

Value assigned to an atom such that the sum of the covalent radii of atoms A and B is (approximately) the A-B bond length.

critical pressure

The lowest pressure required to transform a gas into a liquid at the critical temperature.

critical temperature

One of three parameters (critical pressure and critical molar volume being the other two) defining the point at which random thermal molecular motion become so violent that attractive forces are unable to bring about condensation even when the molecules are squeezed together; a temperature above which a vapor cannot be turned into a liquid no matter how much pressure is applied.

Glossary created by David Shaw (Madison Area Technical College) for The Chemistry Place.

Information Please® Chemistry Place, ©2005 Pearson Education, Inc. All Rights Reserved.