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]

Q 7 :

Arrange the following compounds in increasing order of their dipole moment:  

${\text{HBr, H}}_2{\text{S, NF}}_3{\text{ and CHCl}}_3$                                        [2025]
 

• ${\text{NF}}_3<\text{HBr}<{\text{H}}_2\text{S}<{\text{CHCl}}_3$

   

• ${\mathrm{CHCl}}_3<{\text{NF}}_3<\text{HBr}<{\text{H}}_2\text{S}$

   

• $\text{HBr}<{\text{H}}_2\text{S}<{\text{NF}}_3<{\text{CHCl}}_3$

   

• ${\text{H}}_2\text{S}<\text{HBr}<{\text{NF}}_3<{\text{CHCl}}_3$

   

Q 8 :

Among ${\mathrm{SO}}_2,{\mathrm{NF}}_3,{\mathrm{NH}}_3,{\mathrm{XeF}}_2,{\mathrm{ClF}}_3$ and ${\mathrm{SF}}_4$, the hybridization of the molecule with non-zero dipole moment and highest number of lone-pairs of electrons on the central atom is                      [2025]
 

• $s{p}^3$

   

• $ds{p}^2$

   

• $s{p}^3{d}^2$

   

• $s{p}^{3}d$

   

Q 9 :

Statement I: Dipole moment is a vector quantity and by convention it is depicted by a small arrow with tail on the negative centre and head pointing towards the positive centre.

Statement II: The crossed arrow of the dipole moment symbolizes the direction of the shift of charges in the molecules.

In the light of the above statements, choose the most appropriate answer from the options given below:               [2023]

• Both Statement I and Statement II are correct

   

• Statement I is correct but Statement II is incorrect

   

• Statement I is incorrect but Statement II is correct

   

• Both Statement I and Statement II are incorrect

   

Q 10 :

The pair from the following pairs having both compounds with net non-zero dipole moment is          [2023]

• 1,4-Dichlorobenzene, 1,3-Dichlorobenzene

   

• Benzene, anisidine

   

• ${\mathrm{CH}}_2{\mathrm{Cl}}_2$, ${\mathrm{CHCl}}_3$

   

• cis-butene, trans-butene