Carbon and Its Compounds Chemical Properties
These notes are based on the chapter Carbon and its Compounds from class 10 science of NCERT book and CBSE syllabus.
- Combustion reaction
- Addition reaction
- Subsitution reaction
Combustion Reaction
Carbon and carbon compounds give carbon dioxide, vapor, heat and light on burning in air. Following are some of the examples of combustion reaction of organic compounds:
C + O2 ⇨ CO2 + Heat + Light
CH4 + 2O2 ⇨ CO2 + 2H2O + Heat + Light
CH3CH2OH + O2 ⇨ CO2 + H2O + Heat + Light
Oxidation
In combustion reaction, organic compounds are oxidized in the presence of oxygen. The following example is different because alkaline KMnO4 is the oxidizing agent in this reaction.
CH3CH2OH + (Alkaline KMnO4/Acidified K2Cr2O7) ⇨ CH3COOH
As organic compounds produce high energy on combustion, many of them are used as fuel for domestic and industrial purposes. Fuels such as petrol, diesel and CNG (Compressed Natural Gas) are composed of organic compounds. Even firewood and cowdung contain organic compounds and hence are used as fuel.
Addition Reaction
Formation of larger molecules by addition of more radicals is known as addition reaction. For example; ethene is converted into ethane when heated with the catalyst nickel.
CH2=CH2 + H2 + (Nickel catalyst) ⇨ CH3−CH3
When ethene undergoes addition reaction with chlorine, it gives dichloroethane.
Substitution Reaction:
Replacement of a functional group or any atom by another atom or functional group is known as substitution reaction. Substitution reactions are single displacement reactions.
When methane reacts with chlorine gas in the presence of sunlight, it gives chloromethane and hydrogen chloride.
CH4 + Cl2 + Sunlight ⇨ CH3Cl + HCl
Similarly, ethane gives chloroethane when it reacts with chlorine in the presence of sunlight.
C2H6 + Cl2 + Sunlight ⇨ C2H5Cl + HCl