Carbon and Its Compounds
Class 9: science
Introduction to Carbon, Sources of Carbon, Nature of Carbon (Catenation, Allotrops & Allotropy), Physical properties of Carbon, Organic and Inorganic Compounds, Difference between Organic and Inorganic Compounds, Uses of organic compounds in daily life
Introduction to Carbon
Carbon is a very special element found everywhere around us! It is the building block of life, meaning all living things are made of carbon. Carbon is represented by the symbol \(C\) and is present in the air (as carbon dioxide), in the earth (like coal), and in living things (like plants and animals). Carbo is a black-colored non-metal (Coal). The atomic number of Carbon is 12 and has 6 protons, 6 electrons and 6 neutrons.
Sources of Carbon
1. Natural Sources:
- Air: Carbon dioxide gas in the atmosphere.
- Soil: Organic matter like dead plants and animals.
- Fossil Fuels: Coal, petroleum, and natural gas.
2. Living Things: All plants and animals contain carbon.
3. Food: Foods like fruits, vegetables, and grains are rich in carbon compounds.
Nature of Carbon
1. Catenation
Carbon can bond with itself to form long chains, rings, or complex structures. This property is called catenation and is why there are so many carbon compounds.
2. Allotropes of Carbon
Allotropes are different forms of the same element.
- Diamond: Hard and shiny, used in jewelry and cutting tools.
- Graphite: Soft and slippery, used in pencils and as a lubricant.
- Fullerenes: Special forms of carbon with a cage-like structure, used in technology and medicines.
3. Allotropy
The property of an element to exist in different forms is called **allotropy**. Carbon’s allotropy gives us materials with very different properties, like diamond and graphite!
General Properties of Carbon
The physical and chemical properties of Carbon are as follows.
1. Physical Properties
- Appearance: Pure carbon can be shiny (diamond) or dull (graphite).
- Hardness: Diamond is the hardest natural substance, while graphite is soft.
- Conduction: Graphite conducts electricity, but diamond does not.
- Density: Diamond is very dense; graphite is less dense.
2. Chemical Properties
a. Combustion:
Carbon forms Carbon dioxide in excessive amounts of Oxygen. But if the amount of Oxygen is insufficient it forms Carbon monoxide.
b. Reaction with Metals
Carbon reacts with active metals and forms metal carbide.
c. Reducing Property
Carbon removes oxygen from metal oxide (less reactive metal oxides). This property of carbon is called the reducing property.
d. Reaction with steam
When carbon is heated at \(1000^0 \text(c)\) with water steam it forms a mixture of carbon monoxide and hydrogen gas. The mixture is called water gas.
Organic and Inorganic Compounds
1. Organic Compounds
These are compounds that contain carbon and are usually found in living things. Examples: methane, sugar, fats, proteins, and oils. The branch of chemistry that deals with organic compounds is called Organic Chemistry.
2. Inorganic Compounds
These are compounds that do not contain carbon (or have very little carbon). Examples: water (H₂O), salt (NaCl), and carbon dioxide (CO₂).
Difference Between Organic and Inorganic Compounds
The differences between organic and inorganic compounds are given below in the table.
| Feature | Organic Compounds | Inorganic Compounds |
| Contains Carbon? | Always contains carbon | May or may not contain carbon |
| Found in | Living things (plants, animals) | Non-living things (minerals) |
| Examples | Sugar, fats, proteins | Salt, water, carbon dioxide |
| Structure | Complex and large | Simple and small |
Uses of Organic Compounds in Daily Life
In our daily life, we use organic compounds almost everywhere. Some of them are listed below.
1. Food: Carbohydrates, proteins, and fats provide us with energy.
2. Clothing: Cotton, wool, and silk are organic materials.
3. Medicines: Many medicines are organic compounds.
4. Fuel: Petrol, diesel, and natural gas are organic compounds.
5. Plastic: Used to make bottles, bags, and containers.
