Q 1 :    

Given below are two statements:

 

Statement - I: Noble gases have very high boiling points.

 

Statement -II: Noble gases are monoatomic gases. They are held together by strong dispersion forces. Because of this they are liquefied at very low temperature. Hence, they have very high boiling points.

 

In the light of the above statements, choose the correct answer from the options given below:              [2024]

• Statement I is false but Statement II is true.

   

• Both Statement I and Statement II are true.

   

• Statement I is true but Statement II is false.

   

• Both Statement I and Statement II are false.

   

Q 2 :    

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).

 

Assertion (A): ${\mathrm{NH}}_3$ and ${\mathrm{NF}}_3$ molecule have pyramidal shape with a lone pair of electrons on nitrogen atom. The resultant dipole moment of ${\mathrm{NH}}_3$ is greater than that of ${\mathrm{NF}}_3$.

 

Reason (R): In ${\mathrm{NH}}_3$, the orbital dipole due to lone pair is in the same direction as the resultant dipole moment of the N-H bonds. F is the most electronegative element.

 

In the light of the above statements, choose the correct answer from the options given below:              [2024]

• (A) is true but (R) is false

   

• Both (A) and (R) are true but (R) is NOT the correct explanation of (A)

   

• (A) is false but (R) is true

   

• Both (A) and (R) are true and (R) is the correct explanation of (A)

   

Q 3 :    

Select the compound from the following that will show intramolecular hydrogen bonding.             [2024]

• 

   

• ${\mathrm{H}}_2\mathrm{O}$

   

• ${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}$

   

• ${\mathrm{NH}}_3$

   

Q 4 :    

Which one of the following molecules has maximum dipole moment?                   [2024]

• ${\mathrm{PF}}_5$

   

• ${\mathrm{NF}}_3$

   

• ${\mathrm{NH}}_3$

   

• ${\mathrm{CH}}_4$

   

Q 5 :    

Number of compounds/species from the following with non-zero dipole moment is _____

${\text{BeCl}}_2,{\text{BCl}}_3,{\text{NF}}_3,{\text{XeF}}_4,{\text{CCl}}_4,{\text{H}}_2\text{O},{\text{H}}_2\text{S},\text{HBr},{\text{CO}}_2,{\text{H}}_2,\text{HCl}$                    [2024]

Q 6 :    

Number of compounds from the following with zero dipole moment is ________.

$\text{HF},{\text{H}}_2,{\text{H}}_2\text{S},{\text{CO}}_2,{\text{NH}}_3,{\text{BF}}_3,{\text{CH}}_4,{\text{CHCl}}_3,{\text{SiF}}_4,{\text{H}}_2\text{O},{\text{BeF}}_2$                    [2024]