organic compounds of hydrogen and carbon, whose densities, boiling points, and freezing points increase as their molecular weights increase. Although composed of only two elements. hydrocarbons exist in a variety of compounds because of the strong affinity of the carbon atom for other atoms and for itself. The smallest molecules of hydrocarbons are gaseous; the largest are solids. Petroleum is a mixture of many different hydrocarbons.
F a group of organic substances including all substances consisting only of the elements carbon and hydrogen. The most important main groups are aliphatic and aromatic hydrocarbons of which the latter generally has the most serious harmful effects.
A class of compounds that contain hydrogen and carbon. This group of compounds includes the naturally occurring hydrocarbons produced by plankton, as well as many petroleum-based products like gasoline and motor oil. Chlorinated hydrocarbons, a subclass of hydrocarbons, are human derived and generally toxic.
(3) any of a vast family of compounds containing carbon and hydrogen in various combinations, found especially in fossil fuels. Hydrocarbons in the atmosphere resulting from evaporation and incomplete combustion may be a source of air pollution.
Organic molecules containing hydrogen and carbon. Released during the incomplete combustion of organic fuels. React with nitrogen oxides and sunlight to form photo- chemical oxidants in photochemical smog.
an extensive group of chemicals that always include the elements hydrogen and carbon. Natural sources of hydrocarbons are the by-products of digestion and decomposition (e.g., rotting, spoiling, and putrefying). Coal, natural gas, oil, sugar, starches, and plastics are all composed of hydrocarbons. The incomplete combustion of hydrocarbons from fossil fuels contributes to our pollution and global warming problems.
An organic compound of hydrogen and carbon, including oil, gas and condensate. Return to the top of the page. IN SITU : In the natural or original position. Applied to a rock, soil, or fossil when occurring in the situation in which it was originally formed or deposited.
An organic compound of hydrogen and carbon. HC emissions in exhaust gases are undesirable and are leglislated for. They are known to be carcinogenic but can be removed from the exhaust gas by use of a catalyst.
This refers to all petroleum-based products, such as fuels, oil and grease. It is used at sites for heating, power generation and vehicles. If these products are not handled or stored properly, there can be leaks and spills, which contaminate soil and water.
Chemical compounds consisting of carbon and hydrogen. There are many different hydrocarbons, mainly extracted from petroleum. Hydrocarbons are increasingly replacing freons (CFCs and HCFCs) as cooling agents and insulation gases. They do not contribute to ozone depletion and contribute only negligibly to the greenhouse effect. Most hydrocarbons are highly flammable, and many are hazardous to health.
any compound containing only hydrogen and carbon (eg. methane, CH4; benzene, C6H6) aromatic - any organic molecule that contains a benzene ring (or similar cyclic structure) aliphatic - any organic molecule that doesn't contain an organic benzene ring (or similar cyclic structure)
Compounds found in fossil fuels that contain carbon and hydrogen in various combinations. They are major air pollutants and some may be carcinogenic. Fossil fuels, glues, paints, and solvents contain hydrocarbons. Most people use the terms "hydrocarbon" and "volatile organic compounds" (or VOCs) to mean the same thing.
Organic chemical compounds of hydrogen and carbon whose densities, boiling points, and freezing points increase as their molecular weights increase. The molecular structure of the most common petroleum hydrocarbon compounds varies from the simplest - methane, a constituent of natural gas - to the very heavy and complex.
Hydrocarbon (HC) exhaust emissions are a product of incomplete combustion of a hydrocarbon fuel such as gasoline, diesel, natural gas, and propane. Hydrocarbon emissions can also occur from evaporation of liquid hydrocarbons. HC emissions contribute to the formation of ground level ozone which can cause serious damage to human health and vegetation. See also Causes of Excess Hydrocarbons.
Volatile organic compounds that react with nitrogen oxides (NOx) in the presence of sunlight to form ground-level ozone, a serious lung irritant. Hydrocarbon emissions failures can result from fuel combustion problems that allow unburned fuel to escape from a vehicle's exhaust pipe.
organic chemical compounds that consist only of carbon and hydrogen and are a major component of petroleum products, natural gas and coals. A number of exhaust hydrocarbons are toxic, with the potential to cause cancer.
Organic chemical compounds that consist only of carbon and hydrogen. Hydrocarbons are usually major components of petroleum products, natural gas, and coals. Hydrocarbons that are not burnt completely during combustion contribute to air pollution.
chemicals containing only carbon and hydrogen. These are of prime economic importance because they encompass the constituents of the major fossil fuels, petroleum and natural gas, as well as plastics, waxes, and oils. In urban pollution, these components--along with NOx and sunlight--contribute to the formation of tropospheric ozone.
Compounds containing various combinations of hydrogen and carbon atoms. They may be emitted into the air by natural sources (e.g., trees) and as a result of fossil and vegetative fuel combustion, fuel volatilization, and solvent use. Hydrocarbons are a major contributor to smog. Hydrocarbons include aromatics and volatile organic compounds, many of which are toxic.
Strictly speaking, organic molecules consisting of just carbon and hydrogen; often loosely applied also to derivatives of hydrocarbons containing oxygen, halogens, etc. The atmospheric burden of hydrocarbons is provided from both natural and anthropogenic emissions.