NCERT Class X Science Class: Chapter –4. Carbon and its Compounds – Part-10

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Question 39:

Ethane is formed when ethanol at 443 K is heated with excess of concentrated sulphuric acid. What is the role of sulphuric acid in this reaction? Write the balanced chemical equation of this reaction.

Answer:

Question 40:

Carbon, Group (14) element in the Periodic Table, is known to form compounds with many elements.

Write an example of a compound formed with

  1. Chlorine (Group 17 of Periodic Table)

  2. Oxygen (Group 16 of Periodic Table)

Answer:

(a) Carbon tetrachloride :

Image structure of carbon tetrachloride (CCl 4)

Image Structure of Carbon Tetrachloride (CCl 4)

Image structure of carbon tetrachloride (CCl 4)

(b) Carbon dioxide :

Image structure of Carbon dioxide (CO 2)

Image Structure of Carbon Dioxide (CO 2)

Image structure of Carbon dioxide (CO 2)

Question 41:

In electron dot structure, the valence shell electrons are represented by crosses or dots.

  1. The atomic number of chlorine is 17. Write its electronic configuration

  2. Draw the electron dot structure of chlorine molecule.

Answer:

(a)

K L M structure

K L M Structure

K L M structure

(b)

Image dot structure of chlorine molecule

Image Dot Structure of Chlorine Molecule

Image dot structure of chlorine molecule

Question 42:

Catenation is the ability of an atom to form bonds with other atoms of the same element. It is exhibited by both carbon and silicon. Compare the ability of catenation of the two elements. Give reasons.

Answer:

Carbon exhibits catenation much more than silicon or any other element due to its smaller size which makes the bonds strong while the bonds are comparatively weaker due to its large size.

Question 43:

Unsaturated hydrocarbons contain multiple bonds between the two and show addition reactions. Give the test to distinguish ethane from ethene.

Answer:

The two can be distinguished by subjecting them to the flame. Saturated hydrocarbons generally give a clear flame while unsaturated hydrocarbons give a yellow flame with lots of black smoke.

Question 44:

Match the reactions given in Column (A) with the names given in column (B).

Matching Reactions Q
Matching reactions Q

Column (A)

Column (B)

A.

i

Addition reaction

B.

ii

Substitution reaction

C.

iii

Neutralisation reaction

D.

iv

Esterification reaction

Answer:

Matching Reactions Ans
Matching reactions Ans

Column (A)

Column (B)

A.

iv

Esterification reaction

B.

i

Addition reaction

C.

ii

Substitution reaction

D.

iii

Neutralisation reaction