Huwebes, Disyembre 3, 2015

This blog will show information about alkanes. But first let us analyze  hydrocarbons.


Hydrocarbons
Most of the compounds in crude oil are hydrocarbons. This means that they only contain hydrogen and carbon atoms, joined together by chemical bonds. There are three different types of hydrocarbon, but most of the ones in crude oil are alkanes.
As mentioned, there are three different types of hydrocarbon and those are alkanes, alkenes, and alkynes. We will focus more on alkanes.
Each of these atoms are linked together exclusively by single bonds. The alkanes are a family of hydrocarbons that share the same general formula. This is:

CnH2n+2



Alkanes are saturated hydrocarbons. Saturated compound, as mentioned is a chemical compound that are linked together exclusively by single bonds.This makes them relatively unreactive, apart from their reaction with oxygen in the air, which we call burning or combustion.

Alkyl Groups

If a hydrogen is removed from an alkane, it can be used as a substituent functional group called an alkyl group. Alkyl groups are named by dropping the -ane suffix of the alkanes and adding the suffix -yl. 



Risks of Alkanes:
                Alkanes may always benefit human needs in everyday life but it can also harm human life even in nature too. In result, the nature is affected and so we are. One of the most useful alkane is methane. When being applied in life we should be more careful handling it because it can easily explode.

1. Greenhouse Gases
                Through combustion alkanes contributes huge amount of carbon oxide. Anaerobic decomposition of plants and animal remains contributes methane.  Alkanes are converted to CFCs to be used as propellants in aerosols and as refrigerant gases. It contributes  15- 20% to the greenhouse effect.

2. Less reactive than acids.
                This is because the backbone carbon atoms in alkanes have attained their octet of electrons through forming four covalent bonds. They are saturated.To make alkanes react, the input of additional energy is needed; either through heat or radiation. A lot of energy is needed to break their bonds

Alkanes as generally very unreactive and their most important reaction is combustion with oxygen.
eg:
octane-> hexane +ethene
Ethene is a very important alkene. It’s used to make ethanol and many other important substances in industry.


3. Hazards of Alkanes
Alkanes produces asphxiation, potential carcinogen, flammable, potential explosion hazard that can cause harm. Methane is also considered as hazard because it can be explosive when mixed with air (1 – 8% CH4).


Benefits and Advantages of Alkanes:
                Alkanes benefits human needs in their everyday life. It seems to be present all the time. Even in nature alkanes occurs.

1. Good Fuel.
     They're mostly used as fuel oils. For instances, butane is often used in lighters and propane is often used for powering grills. Other examples of alkane gases are methane, ethane, and propane but the most commonly used is butane.  Fossil fuels contain many different types of alkanes as well as other organic molecules which makes them a sought after fuel source.

2. Higher Alkanes are good lubricants.


3. They are antiseptic for external use.

4. Chemical energy is easily released (used for power).


                       Alkanes Everywhere
In Biological Occurrence
Archaea are single-celled organisms lacking nuclei and are therefore prokaryotes. It produces large quantities of methane by the metabolism of carbon dioxide or other oxidised organic compounds.


Alkanes also play a role in biology of the three eukaryotic groups of organisms: fungi, plants and animals. Some specialised yeasts, an example is Candida tropicale, can use alkanes as a source of carbon and/or energy. In plants it is the solid long-chain alkanes that are found; they form a firm layer of wax, the cuticle, over areas of the plant exposed to the air. This protects the plant against water loss, while preventing the leaching of important minerals by the rain. It is also a protection against bacteria, fungi and harmful insects — the latter sink with their legs into the soft waxlike substance and have difficulty moving. The shining layer on fruits such as apples consists of long-chain alkanes.

Water forms droplets on a thin film of alkane wax on the skin of the apple.


Ecological relations
Early spider orchid
One example in which both plant and animal alkanes play a role, is the ecological relationship between the sand bee (Andrena nigroaenea) and the early spider orchid (Ophrys sphegodes); the latter is dependent for pollination on the former. Sand bees use pheromones in order to identify a mate; in the case of A. nigroaenea, the females emit a mixture of tricosane (C23H48), pentacosane (C25H52) and heptacosane (C27H56) in the ratio 3:3:1, and males are attracted by specifically this odor. The orchid takes advantage of this mating arrangement to get the male bee to collect and disseminate its pollen; parts of its flower not only resemble the appearance of sand bees, but also produce large quantities of the three alkanes in the same ratio as female sand bees.

Early spider orchid


Applications

Alkanes are very useful up to this day. The first four alkanes are used mainly for heating and cooking purposes, and in some countries for electricity generation. Methane and ethane are the main components of natural gas; they are normally stored as gases under pressure. It is however easier to transport them as liquids: this requires both compression and cooling of the gas. Methane is the simplest possible alkane (the parent molecule).  Did you know that the candle wax is made from alkane? All waxes used in candles are generally composed of straight-chain alkanes.
Propane and butane can be liquefied at fairly low pressures, and are well known as liquified petroleum gas (LPG). Propane, for example, is used in the propane gas burner, butane in disposable cigarette lighters. It’s like the main purpose of alkane is giving warmth and fire to us. The two alkanes are used as propellants in aerosol sprays.

From pentane to octane the alkanes are reasonably volatile liquids. They are used as fuels in internal combustion engines, as they vaporise easily on entry into the combustion chamber without forming droplets which would impair the unifomity of the combustion.






Have you tried to have a spa to relax? How about relaxing and healing? Did you know that in Azerbaijan, people bathe themselves at a warm crude oil? According to locals, sitting in this liquid commodity is great for one's health.

The oil "can heal more than seventy diseases, including neurological diseases, skin conditions and impotence,"Hashim Hashimov, a medical specialist at Naftalan Health Center in Baku, Azerbaijan told Reuters. It is used for health therapy.


References:

 http://www.businessinsider.com/crude-oil-baths-in-azerbaijan-2015-7