Important Questions For Class 10 Science Chapter 4- Carbon and its Compounds

VERY SHORT ANSWER TYPE QUESTIONS (1 Mark)

Q1. What is a hydrocarbon?
Ans. It is a compound of hydrogen and carbon.

Q2. Give different forms in which carbon occurs in nature.
Ans. Carbon occurs in free form e.g., graphite and diamond in combined form like carbon dioxide, carbonates, etc.
In earth’s crust–0.02% and in atmosphere–0.03%.

Q3. Name two types of hydrocarbon.
Ans. Hydrocarbon – Saturated and unsaturated.

Q4. What are covalent bonds?
Ans. Bond which are formed by sharing of a pair of electrons between two atoms is called covalent bonds.

Q5. What is catenation?
Ans. Carbon has the unique ability to form bonds with the other atoms of carbon which gives rise to large molecules. This property of self linking is called catenation.

Q6. Name two allotropes of carbon.
Ans. Two allotropes are – Crystalline and amorphous
Crystalline form – Diamond and graphite.
Amorphous form – Charcoal, coal, coke.

Q7. Why covalent compounds have low melting and boiling points?
Ans. As the bond is formed by sharing of electrons between two atoms. Intermolecular forces are small between the covalent compounds. These bonds break easily.

Q8. Define oxidising agents.
Ans. Some substances are capable of adding oxygen to others. These substances are known as oxidising agents.
Example: alkaline KMnO4 and acidified K2Cr2O7.

Q9. Give the reaction to show how alcohol is converted into carboxylic acid.

Q10. Identify the compound

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Ans. Propyne.

Q11. Name the compound

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Ans. Benzene, C6H6.

Q12. Give two properties of ethanol.
Ans. (a) Liquid at room temperature
(b) Soluble in H2O in all proportions

Q13. Give the formula for the functional group of aldehyde.

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Q14. What are heteroatoms?
Ans. An element or group of elements which replaces one or more hydrogen (H) atoms from hydrocarbon, such that valency of carbon remains satisfied.
Example: CH4 ⎯→ CH3 – OH
Hence, —OH is a heteroatom.

Q15. Define catalyst.
Ans. Catalyst are substances that cause a reaction with a change in rate of reaction, without itself undergoing any change.
Example: Micelle acts as a catalyst to convert unsaturated hydrocarbon into
saturated hydrocarbon.

Q16. Complete the following reaction:

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Ans.

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Q17. Give the full form of IUPAC.
Ans. IUPAC → International Union of Pure and Applied Chemistry.

Q18. How can esters be converted into soap?
Ans. By saponification reaction, by adding/reacting ester with NaOH.

Q19. How can we convert CH3CH2OH into C2H4 ?
Ans. By adding conc. sulphuric acid into it which acts as dehydrating agent and removes water from it.

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Q20. Give two properties of ionic compounds.
Ans. (i) High melting point and high boiling point.
        (ii) Can conduct electricity.

Q21. What is the melting point of acetic acid?
Ans. M.P. = 290 K.

Q22. Name the given compound

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Ans. 2-Butanone.

Q23. How can you convert ethene into ethane?
Ans. By adding hydrogen to ethene in the presence of a catalyst.

Q24. What is addition reaction? Give one example.
Ans. The process of adding hydrogen across the double bonds of unsaturated hydrocarbons is called addition reaction.

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Q25. What is esterification reaction?
Ans. The reaction in which alcohol reacts with carboxylic acid to produce a new compound called ester is called esterification.

Q26. Give two uses of methane gas.
Ans. (i) It is used as a fuel (ii) It is the major component of biogas and CNG.

Q27. What is isomerism?
Ans. A property in which a compound can exist in different structural formula but its molecular formula remains the same.

Q28. Why can’t we test hard water with detergents?
Ans. Detergents form lather with both hard and soft water hence we cannot distinguish between them.

Q29. What is hydrophilic?
Ans. The substance showing attraction towards water is called hydrophilic.

Q30. Name the second member of alkyne series.
Ans. Propyne

Q31. Give the names of the functional group

(i) —CHO (ii) —C==O

Ans. (i) Aldehyde (ii) Ketone

Q32. The structural formula of an ester is

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Name the alcohol and the acid from which it would have been formed.

Ans. Alcohol is C2H5OH ethanol
Acid is H3C—H2C—COOH propanoic acid.

Q33. Give the IUPAC name of acetic acid and propyl alcohol.
Ans. Acetic acid – Ethanoic acid
Propyl alcohol – Propanol

Q34. What will happen to the litmus solution in carboxylic acid?
Ans. Red litmus remains the same but blue litmus changes to red.

Q35. Give the electron dot structure of CH3Cl and C2H2.

Ans.

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Q36. Draw the electron dot structure of N2 and NH3.

Ans.

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Q37. Why do soaps form scum when added to hard water?
Ans. Hard water contains carbonate and sulphate salts of magnesium or sodium ions which react with the soap molecule to form a compound which is insoluble in water. Hence soaps form scum with hard water.

Q38. What happens when ethanol burns in air?
Ans. Ethanol burns to form carbon dioxide and water.

Q39. Give the IUPAC name and write the functional group present in vinegar.
Ans. Vinegar IUPAC name is acetic acid CH3COOH Functional group –COOH

Q40. A compound has a molecular formula C2H6O. It is used as a fuel. Name the compound and name its functional group.
Ans. C2H6O is an alcohol, i.e. ethanol C2H5OH Functional group is —OH.

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