Chemistry Class-11: Chapter – 4. Chemical Bonding and Molecular Structure Part – 8 (For CBSE, ICSE, IAS, NET, NRA 2023)

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V. Assertion and Reason Type

In the following questions a statement of Assertion (A) followed by a statement of Reason (R) is given. Choose the correct option out of the choices given below each question.

Question: 57

Assertion (A) : Sodium chloride formed by the action of chlorine gas on sodium metal is a stable compound.

Reason (R) : This is because sodium and chloride ions acquire octet in sodium chloride formation.

(i) A and R both are correct, and R is the correct explanation of A.

(ii) A and R both are correct, but R is not the correct explanation of A.

(iii) A is true but R is false.

(iv) A and R both are false.

Answer: (i)

Question: 58

Assertion (A) : Though the central atom of both molecules are hybridised, bond angle is greater than that of .

Reason (R) : This is because nitrogen atom has one lone pair and oxygen atom has two lone pairs.

(i) A and R both are correct, and R is the correct explanation of A.

(ii) A and R both are correct, but R is not the correct explanation of A.

(iii) A is true but R is false.

(iv) A and R both are false.

Answer: (i)

Question: 59

Assertion (A) : Among the two bonds in molecule, the energy required to break the first bond and the other bond is the same.

Reason (R) : This is because the electronic environment around oxygen is the same even after breakage of one bond.

(i) A and R both are correct, and R is correct explanation of A.

(ii) A and R both are correct, but R is not the correct explanation of A.

(iii) A is true but R is false.

(iv) A and R both are false.

Answer: (iv)

VI. Long Answer Type

Question: 60

(i) Discuss the significance/applications of dipole moment.

(ii) Represent diagrammatically the bond moments and the resultant dipole moment in and .

Answer:

Question: 61

Use the molecular orbital energy level diagram to show that would be expected to have a triple bond, , a single bond and , no bond.

Answer:

Question: 62

Briefly describe the valence bond theory of covalent bond formation by taking an example of hydrogen. How can you interpret energy changes taking place in the formation of dehydrogenate?

Answer:

Question: 63

Describe hybridisation in the case of and . The axial bonds are longer as compared to equatorial bonds in whereas in both axial bonds and equatorial bonds have the same bond length. Explain.

Answer:

Question: 64

(i) Discuss the concept of hybridisation. What are its different types in a carbon atom?

(ii) What is the type of hybridisation of carbon atoms marked with star.

(a)

(b)

(c)

(d)

(e)

Answer: