Carbon and it`s reactions

Introduction

Carbon is the most versatile compound in nature as  it demonstrates a wide range of reactions with many other compounds available in nature. Its versatility is linked with the ability to form multiple bond types; single, double, and triple. It also has the ability to form a variety of chains such as straight chains,  branched chains,  rings (if it is connected to other carbon atoms) . Such a kind of ability to form flexible bonding help in the formation of  a variety of structures. The flexibility also allows them to mold into a variety of day-to-day used products ranging from pencil to the gigantic machinery used in industries. As an element, we can observe carbon in  a variety of forms such as coal, soot in addition to its purest  forms of carbon through diamonds. Carbon also occurs in a form, discovered only recently, known as fullerenes or buckyballs. Buckyball carbon holds the promise for opening a whole new field of chemistry.

 

Extraction of carbon

Carbon is not usually extracted in its purest form because it is found combined with many other elements including metals. If a metal is less reactive than carbon, it is extracted from its oxide through heating with carbon. The carbon displaces the metal from the compound, and removes the oxygen from the oxide which in turn help to  leave the metal aside. On the other hand, diamond, graphite, and other forms of carbon are extracted directly from the mines, nevertheless, few carbon compounds can also be prepared in laboratory settings. Synthetic diamonds, for example, are made by heating carbon at high pressure (800,000 pounds per square inch and temperatures about 2,700 °C). The carbon is heated and squeezed in the same way as the organic material is heated and squeezed inside the earth.  As diamond is highly expensive and in demand, 1/3 of all diamonds used are synthetically produced.

 

Uses of carbon compounds

  1.  Since diamond is a rock-hard structure, it is used to cut glass and metals. Diamonds can also be used while polishing and grinding of hard surfaces. 

  2. Graphite is used in many industrial settings, however, the maximum share of the graphite goes to pencil industries. It is also used in-between the industrial machines where the machinery parts undergo a constant rubbing. This is because, carbon allows the parts to slide over without friction. It is also used as a refractory material that can resist very high temperatures by reflecting heat away from itself. Some nuclear power plants also use Graphite.

  3. The powdered(Amorphous)  forms of carbon are used in black colour inks and some colouring agents such as pigments. Carbon is also added to rubber tyres and some polishes.

  4. In the hospital settings,  activated charcoal is used to remove the organophosphorus poisons from patient’s stomach. This is due to the ability of carbon to absorb the poison when used as activated charcoal.

 

Carbon reactions

Combustion Reactions

Combustion is the process of burning carbon and its compounds in the presence of oxygen. While heating, the reaction produces a lot of heat and light energy. Nevertheless, carbon alone is not highly combustible instead, the presence of oxygen can escalate the process of combustion. A combustion reaction is exemplified as ;

  1. Carbon + O2(oxygen) ⇨ CO2 + heat and light

  2. C3H8 (propane) + 5O2 = 3CO2 + 4H2O+ heat and light. Propane is used as LPG(liquid petroleum gas)  in the domestic and commercial kitchens for cooking. During the combustion,  saturated hydrocarbons produce a clear blue flame and the unsaturated hydrocarbons burn with a yellow flame to indicate the presence of carbon. There are 2 types of combustion of hydrocarbons, complete combustion and incomplete combustion. Complete combustion is possible only under a  sufficient oxygen (air), and incomplete combustion occurs while there is oxygen deficit but the hydrocarbon is in excess.

 

Oxidation Reactions

Oxidation is a chemical reaction that takes place in the presence of oxygen in which the carbon gets oxidized but it won’t get burnt. So the thumb rule is that, though combustion is an oxidation reaction, but not every oxidation reaction is combustion. Oxidation is also carried out by using oxidizing agents (Oxidants). Oxidants are substances that oxidize other substances while undergoing reduction by themselves. For instance, alcohols undergo oxidation in the presence of oxidants like alkaline potassium permanganate (KMnO4) to form carbolic acids. Similarly, ethanol undergoes oxidation to produce acetic acid when heated by an Oxidizing agent like alkaline KMnO4.

 

Addition reactions

The formation of larger molecules by combining radicals is called an addition reaction. During the addition reaction of unsaturated organic compounds, a reagent acts in between the double-bonded or triple bonded carbon atoms. These reagents assist in addition reaction by allowing the unsaturated organic compounds to undergo additional reactions to convert them into saturated. Compounds like alkenes and alkynes contain multiple bonds (C=C, C≡C) between their carbon atoms where the addition reaction will produce a balanced saturation.  For example; ethene is converted into ethane when heated with the catalyst nickel, it is written as ;

 CH2=CH2 + H2 + (Nickel catalyst) ⇨ CH3−CH3. In this case, nickel acts as a catalyst, which will either increase or decrease the rate of a given reaction.

 

Substitution Reaction

Substitution reactions are more popular in the organic chemistry. It is a chemical reaction during which one functional group in a chemical compound is replaced by another functional group. It is also known as a single displacement reaction or a single substitution reaction.  For example ;

 CH4 + Cl2 + Sunlight ⇨ CH3Cl + HCl. Here, the sunlight has UV rays that break down the chlorine into free radicals, which initiates the substitution reaction. These reactions define the chemical properties of carbon compounds.

 

Carbon-14 dating

Organisms and carbon are inseparable as the organism either  takes in or leaves out carbon dioxide . Bulk of  carbon dioxide is made out of carbon-12, but a small  portion consists of carbon-14. Therefore, the living organism always contains a very small amount of radioactive carbon( carbon-14) which can be detected by a carbon detector and it would record radiation given off by the carbon-14 in the organism. When an organism dies, it no longer uses  carbon dioxide and no new carbon-14 is added, and the old carbon-14 slowly decays into nitrogen. Consequently, the  amount of intake of carbon-14 also  decreases gradually. Based on the degree at which C-14 is slowly reducing the emission of radiocarbon can determine  how long the organism has been dead.

 


Read More

1         

versatile nature of carbon

2

Carbocation

3

Carbon and its reactions

4

Important trends and anomalous behavior of carbon

 

 

Check your understanding

  1. How is Synthetic diamonds prepared?

  2. Explain the combustion reaction of carbon compounds.

  3. What is the outcome of addition reaction of a carbon? Explain with example.

  4. Why is carbon versatile?

  5. Explain the Uses of carbon compounds.

  6. Name some items that contains carbon.

 



img-1


img-1


img-1

Course List