Hydrocarbons are the simplest alkane, a hydrocarbon that contains only
single covalent bonds. Hydrocarbons are compounds whose molecular structure
consists of hydrogen and carbon. The simplest molecule of the alkane is
methane. Methane is a gas at standard temperature and pressure, is a major
component of natural gas (Wilbraham, 1992).
Hydrocarbons can be classified according to a variety of carbon-carbon bonds
they contain. Hydrocarbons with carbon-carbon single bond has called saturated
hydrocarbons. Hydrocarbons with two or more carbon atoms having two or three
bonds called unsaturated hydrocarbons (Fessenden, 1997).
Hydrogen and its compounds, generally divided into three major groups, namely:
1. Hydrogen consists of aliphatic carbon chain that
does not cover cyclic wake. This group is often
referred to as the open-chain hydrocarbons or cyclic hydrocarbons. Examples of
aliphatic hydrocarbons, namely:
C2H6 (ethane) CH3CH2CH2CH2CH3 (pentane)
2. Alicyclic hydrocarbon or cyclic
hydrocarbon composed of carbon atoms arranged in a ring or more.
3. Aromatic hydrocarbons are a special
class of cyclic compounds that are usually described as a ring of six with a
single bond and a double bond bersilih changed. The group is classified
separately from acyclic and aliphatic hydrocarbons because of its unique
physical and chemical properties (Shukri, 1999).
For saturated hydrocarbons, all of the carbon atoms in the alkane has four
single bonds and no lone pairs. The electrons are bound strongly by both atoms.
Consequently, these compounds are quite stable and is also called paraffin
which means less reactive (Wilbraham, 1992).
Carbon-carbon of a hydrocarbon can come together as a chain or a ring.
Saturated hydrocarbons with the atoms together in a straight chain or branched
chain alkanes are classified as. A mean of each straight-chain carbon atoms of
alkanes is tied to no more than two other carbon atoms. A branched-chain
alkanes containing at least one carbon atom bonded to three other carbon atoms
or more (Fessenden, 1997).
Straight-chain alkanes:
CH3 - CH2 - CH3
Branched-chain alkanes:
CH3 - CH - CH2 - CH3
CH3
Compounds of low molecular weight gaseous and liquid, high-molecular-weight
substances are solid. Alkanes are nonpolar substance, a substance that is not
soluble in water with a liquid density of less than 1.0 g / ml. In addition
there is also alkanes alkenes are hydrocarbons which have one or more double
bond carbon-carbon. The compound is said to be saturated because it does not have
the maximum number of atoms that actually can fit any carbon (Pettruci, 1987).
Aliphatic hydrocarbons derived from petroleum, while aromatic hydrocarbons from
coal. All hydrocarbons, aliphatic and aromatic have three general properties,
which are not soluble in water, is lighter than water and burns in air
(Wilbraham, 1992)
Merupkan alkane hydrocarbons from unsaturated aldehyde can be reacted with
acetaldehyde, Zn metal in acid and added H2SO4, following the addition of H2SO4
then changes color changes to dark brown, dense metal that Zn as for being late
due to the influence of H2SO4. This reaction is called reduction Clemensen,
while the reaction is as follows:
O
CH3 - C - H Zn + H2SO4 C2H6
Zn metal were to act as a reductant, whereas concentrated H2SO4 serves as an
oxidant. This is what causes the color change. Acetaldehyde is a group of
easily reduced to aldehyde compounds with the same number of atoms number. Zinc
metal is added to function as a reductant (oxidized), whereas concentrated H2SO4
solution as an oxidant (is reduced).
gas missions that have an influence on human health and global warming is often
not a priority in any policy made by many countries in the world. How badly
actual consequences gas emissions can we trace below.
Indeed, gas emissions from the offerings in human activity is a consequence of
everyday life on planet earth. Emissions that occurred, was not solely derived
from human activities, but also of the natural process. For example, the leaf
respiration, volcanic eruption, the natural life in the woods, spontaneous
fires in the woods, and the biochemical processes that occur in the swamp. The
gas emitted naturally, according to Dr. dr. SKM
Purwaka Rachmadhi School of Public Health, University of Indonesia, Jakarta, is
part of the recycling process that always occurs dynamically in order to
equilibrium naturally.
"For the amount of emissions that the offerings are still within the
limits of the natural ability to recycle re-reschedule, gas emissions will not
significantly disrupt life on Earth. However, if the gas resulting from human
activity has been beyond kepasitas natural recycling, of course cause a buildup
of gas, not only on the micro-environment, but also has led to faltering
balance of the macro environment, which are in the form of global warming that
does not directly result in public health , "said Rachmadhi.
In addition to the indirect effects of the gas,
the gas content types that emissions of any potential direct effect on public
health.
The presence of several components that form gas emissions from motor vehicles
(carbon monoxide, nitrogen gas, and the gas nitrogen oxide gases and
gas-hydrocarbons) and this is a xenobiotic substance (substances foreign to the
human body), also cause a variety of health problems in humans directly.
Carbon monoxide, for example, will cause
interference with the transport of oxygen in the body system. Nitrogen oxide
gases are gases that potentially lower the body's immunity, and hydrocarbon
gases, obviously it can cause irritation, body system disorders and cancer.
Global Warming
According Rachmadhi, global warming began to be
realized when at about the decade of the 1960s to the 1970s, experts are faced
with data regarding the cessation of cooling air. Previously, the earth cools
at a rate of half a degree every year. However, the process of global warming
when it is detected in the northern hemisphere, causing the cooling of the
earth stalled. Since then, conditions continued to global warming which leads
to an increase in air temperature.
The experts who are members of the body of the National Oceanographic and
Atmospheric Administration in the United States, and believes that global
warming caused by the buildup of carbon dioxide in the upper atmosphere as a
result of human activities offering. The presence of carbon dioxide in large
quantities is like to be a shock for the degree of reflection or albedo of the
earth to the sun which allows the earth to avoid overheating. Reflection of the
earth to the sun was due to the reflection of sunlight by dust particles,
clouds, water, snow, and ice.
In addition to carbon dioxide, some other gases are also known to contribute to
global warming. The gases in question, among other things, gas ozone found in
lower layers of the atmosphere, methane, chlorofluorocarbon gases, nitrogen
oxide gases, and water vapor. Clouds are a deterrent sunlight heating the
Earth, it also blocks the release of the reflected heat of the earth so that
played a role in the process of global warming.
According Rachmadhi, it is known that carbon dioxide has the largest
contribution in its effect on global warming, which is as much as 49 percent,
while only 18 per cent methane, chlorofluorocarbon gases by 14 percent,
nitrogen oxide gases 6 percent, and other gases by 13 percent. Thus, it can be
said that of all kinds of gases causing global warming, carbon dioxide is the
most dangerous gases. Conversely, global warming by greenhouse gases such as
carbon dioxide through effect, it is a precondition for human life and most
animals. If this process does not occur, the average air temperature at the
earth's surface is minus 20 degrees Celsius.
However, in the recent period, the earth gets redundant supply of the gases.
The burning of forests and fossil fuels, industry, power generation and motor
vehicle emissions contribute to greenhouse gas carbon dioxide and other gases
into the atmosphere. "The supply of these gases occur in excess and
concentrated in certain places," he said.
Due to presence of Increased Number of People and Development
An increasing number of people and the accompanying development aselerasi, give
rise to the availability of foodstuffs multiplied many times compared to the
past. Traditional farming patterns no longer able to meet the food needs of the
world's insistence, so that agricultural patterns through a revolution that
forced the felling of forest for the purpose of farming land and shelter.
With the opening of farmland that causes tearing down forests absorbing carbon
dioxide through the process of assimilation, increased levels of carbon dioxide
in the atmosphere becomes uncontrollable. Under ordinary circumstances the
forest and vegetation in general is one of the elements that contribute to
transform carbon dioxide into ingredients for growth for plants in the
recycling of carbon. "According to estimates, if the other conditions to
support, required plant 20 billion trees every year to be able to absorb 67
percent of annual emissions of carbon dioxide gas in the United States,"
he said.
In addition to carbon dioxide, chlorofluorocarbon gases, which are a group of
man-made gas, also have an influence on global warming. Chlorofluorocarbon
gases emissions are not the result of human activity offerings. Gas group was
created for several purposes, among them, as the refrigerant (or Freon
dichlorodifluoromethane), solvents in industry, detergent electronic
components, an additive in paint volatile materials, manufacture of rubber
plastic foam (polyurethane foam rubber), and aerosol spray tube. "Although
the amount of chlorofluorocarbon gases is much less than the amount of carbon
dioxide, chlorofluorocarbon each molecule potential greenhouse gas effect by 10
thousand times in comparison with the molecules carbon dioxide gas," he
said.
Once entered into the atmosphere, gases chlorofluorocarbons can last between 75
years up to 110 years. While there, the gas will act to eliminate ozone gas
Earth's protective shield against excessive sunlight. Due to excess sun's effect
on the incidence of changes in climate, animal life and flora. Phytoplankton
and algae food for fish killed by excessive sun this. As a result, gas
absorption kardon dioxide by the amount of water that dead flora also
participated reduced.
Global warming is also a process over which poses some environmental factors
effects on human life, such as the possibility of melting icebergs that will
submerge some parts of the land, climate change resulting in food shortages
population. Continued to take into account is the result of the migration of
the population of the earth as it did in the ancient ice age with the potential
for social unrest mankind globally.
Increasing the temperature of the Earth would result in a very extreme climate
changes on Earth. This can lead to disruption of forests and other ecosystems,
thereby reducing its ability to absorb carbon dioxide in the atmosphere. Global
warming resulting in the melting of icebergs in the polar regions that could
lead to rising sea levels. The greenhouse effect will also lead to rising sea
temperatures that sea water expands and sea level rise occurred which resulted
in the island nation will have a huge influence.
According to the simulation calculations, the greenhouse effect has increased
the Earth's average temperature 1-5 ° C. If the trend of increasing greenhouse
gases remain as it will lead to an increase in global warming between 1.5 to
4.5 ° C around the year 2030. With increasing concentration of CO2 in the
atmosphere, the more heat waves reflected from the Earth's surface is absorbed
the atmosphere. This will result in
earth's surface temperature to rise.
I want to ask about the aliphatic compounds, actually what is the definition of aliphatic compounds? whether it has special characteristics? and aliphatic compounds from which it originated?
BalasHapusThank's for your coments cici, I will to try answer your question but the last question I cant answer...Aliphatic hydrocarbons are carbon compounds chain opens its C and C it allows branched chain. Based on the amount of the bond, aliphatic hydrocarbons, aliphatic compounds are divided into saturated and unsaturated.
BalasHapusa. The compound is a saturated aliphatic C chain aliphatic compounds it contains only single bonds only.
b. Unsaturated aliphatic compounds are aliphatic compounds, varying chain C double bond or triple. If you have duplicate named alkenes and alkynes have triple called. Examples of unsaturated aliphatic hydrocarbons