CBSE – 10th Standard Science

Class 10 Question Bank Chapter 4 – Carbon and its Compounds


Qus 1. How much carbon dioxide is present in the earth’s atmosphere?

Ans. The earth crust has only 0.03% Carbon dioxide present in the atmosphere.

Qus 2. What is the atomic number of carbon?

Ans. The atomic number of carbon is 6.

Qus 3. How many hydrogen atoms are required to form a molecule of hydrogen?

Ans. Two hydrogen atoms are required to form a molecule of hydrogen.

Qus 4. Write the molecule formula of ammonia?

Ans. The molecule of ammonia has the formula NH3.

Qus 5. Name the compound of carbon?

Ans. Methane is the compound of carbon.

Qus 6. What are the uses of methane?

Ans. Methane is widely used as a fuel and is a major component of bio-gas and compressed Natural Gas (CNG).

Qus 7. Why is Carbon is tetravalent?

Ans. Carbon is tetravalent because it has four valence electrons.

Qus 8. What are covalent bonds?

Ans. bonds which are formed by the sharing of an electron pair between two atoms are known as covalent bonds.

Qus 9. Explain the term’ catenation’?

Ans. Carbon has the unique ability to form bonds with other atoms of carbon, giving rise to large molecules. This property is called catenation.

Qus 10. What are saturated compounds.?

Ans. Compounds of carbon, which are linked by only single bonds between the carbon atoms are called saturated compounds

Qus 11. What are unsaturated compounds?

Ans. the Compounds of carbon having double or triple bonds between their

carbon atoms are called unsaturated compounds.

Qus 12. What are structural isomers?

Ans. Compounds with identical molecular formula but different structures are called structural isomers.

Qus 13. What are hydrocarbons?

Ans. All these carbon compounds which contain just carbon and hydrogen are called hydrocarbons.

Qus 14. Explain the term ’Alkenes’?

Ans. The unsaturated hydrocarbons which contain one or more double bonds are called alkenes.

Qus 15. What is homologous series?

Ans. The series of compounds in which the same functional group substitutes for hydrogen in a carbon chain is called a homologous series.

Qus 16. What is propane?

Ans. A compound having three carbon atoms is called Propane.

Qus 17. What are oxidising agents?

Ans. The substances are capable of adding oxygen to others. These substances are known as oxidising agents.

Qus 18. What is substitution reaction?

Ans. When chlorine replaces the hydrogen atoms one by one then the reaction which takes place is called substitution reaction.

Qus 19. What is the other name of Ethanol?

Ans. Ethanol is commonly called alcohol.

Qus20. Explain the term ‘saponification’?

Ans. When treating with sodium hydroxide, which is an alkali, the ester is converted back to alcohol and sodium salt of carboxylic acid. This reaction is known as saponification.


Q.1. What would be the electron dot structure of carbon dioxide which has the formula CO2?

Q.2. What would be the electron dot structure of a molecule of sulphur    which is made up of eight atoms of sulphur? (Hint – The eight atoms of sulphur are joined together in the form of a ring.)

Q.3.Draw the structures for the following compounds.

(i) Ethanoic acid (ii) Bromopentane*

(iii) Butanone (iv) Hexanal.

*Are structural isomers possible for bromopentane?

Q.4. What are the two properties of carbon which lead to the huge number of carbon compounds we see around us?

Q.5. What will be the formula and electron dot structure of cyclopentane?