Carbon compounds can be present in our food, clothing, and even the lead of the pencil we use. It exists in both its free and mixed forms. It can be found as coal or graphite in its basic form.
It produces a vast spectrum of compounds, from tissues to medications, when it combines with other elements.
Before studying the chemical properties of carbon compounds, let us see what carbon is?
Carbon is a very different and surprising element. The symbol of carbon is 'C' while its atomic number is 6.. The electronic configuration of carbon in K and L shells is 2,4. So, it has four valence electrons. Therefore, its valency is also 4.
However, the reactions that these compounds undergo are limited. Some important reactions are discussed here.
Carbon and its compounds burn in the presence of oxygen or air to give carbon dioxide, water vapours, and energy. This process of burning carbon compounds in excess of oxygen to give heat and light is called a combustion reaction.
C + O2 ---------> CO2 + Energy
C2H5OH + 3O2 ---------->2CO2 + 3H2O + Energy
Combustion can be of two types- complete combustion and incomplete combustion.
Most carbon compounds are good fuels.
Due to combustion in the presence of oxygen, we will get a clean bluish flame with saturated hydrocarbons. This will be in the case of complete combustion.
If there is an incomplete combustion of saturated hydrocarbons due to lack of oxygen, a sooty flame will be observed. On the other hand, we will get a yellow flame with smoke in the case of unsaturated hydrocarbons.
The important point to be noted here is that complete combustion of carbon compounds yields CO2 (Carbon Dioxide) gas as the product. However, in the case of incomplete combustion, CO (Carbon Monoxide) is formed. CO is a poisonous gas that has a great affinity to haemoglobin in the blood. It combines with haemoglobin to form a compound called carboxyhaemoglobin. It prevents oxygen from reaching the body cells. This condition is fatal and can lead to the death of a person, also known as carbon monoxide poisoning.
Since methane gas (natural gas) produces a lot of heat during the reaction and does not cause much air pollution, it is used as fuel in homes, transport, and industry. Many vehicles nowadays use CNG to run. The cooking gas (LPG) we use in our homes is mainly an alkane called butane (C4H10).
Addition reaction: The reaction in which an unsaturated hydrocarbon combines with another substance to give a single product is called an addition reaction.
The vegetable oils or cooking oils are unsaturated in the sense that their molecules contain at least one double bond in their structure. Upon passing hydrogen gas through the oil in the presence of a nickel catalyst, the double bond changes to a single bond. Vegetable ghees such as Dalda is an example of this process.