NEETChemistryChemical Bonding and Molecular Structure
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): The resultant dipole moment of NH ₃ is significantly higher than that of NF ₃ . Reason (R): In NH ₃ , the orbital dipole due to the lone pair is in the opposite direction to the resultant dipole moment of the N - H bonds, whereas in NF ₃ they are in the same direction. In the light of the above sta
Options
- ABoth (A) and (R) are true and (R) is the correct explanation of (A)
- BBoth (A) and (R) are true but (R) is not the correct explanation of (A)
- C(A) is true but (R) is false
- D(A) is false but (R) is true
Correct answer
C. (A) is true but (R) is false
Step-by-step solution
Assertion (A) is true: The dipole moment of NH ₃ ( 1.47 D ) is significantly higher than that of NF ₃ ( 0.23 D ). Reason (R) is false: In NH ₃ , nitrogen is more electronegative than hydrogen. The resultant dipole moment of the three N - H bonds points towards nitrogen, which is in the same direction as the orbital dipole due to the lone pair. In NF ₃ , fluorine is more electronegative than nitrogen, so the resultant dipole moment of the three N - F bonds points away from nitrogen, which is in the opposite directio