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 dipole moment of CH ₄ is non-zero, while that of CH ₃ Cl is zero. Reason (R): CH ₄ has a perfectly symmetrical tetrahedral geometry where bond dipoles cancel out, whereas CH ₃ Cl is asymmetrical due to the difference in polarity between C-H and C-Cl bonds. In the light of the above statements,
Options
- ABoth Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A)
- BBoth Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A)
- CAssertion (A) is true but Reason (R) is false
- DAssertion (A) is false but Reason (R) is true
Correct answer
D. Assertion (A) is false but Reason (R) is true
Step-by-step solution
Assertion (A) is false because CH ₄ has a net dipole moment of zero ( = 0 ), not non-zero. In contrast, CH ₃ Cl has a non-zero dipole moment ( 0 ) because the dipoles do not cancel out. Reason (R) is true. CH ₄ is a perfectly symmetrical tetrahedral molecule where all four C-H bond dipoles cancel each other out completely. CH ₃ Cl , however, has one C-Cl bond and three C-H bonds. Because the C-Cl bond has a different dipole moment compared to the C-H bonds, the vector sum of the dipoles is not zero, making the mole