COMEDK2024ChemistryChemical Bonding and Molecular StructureActual
In the following question a statement of Assertion (A) followed by a statement of Reason (R) is given. Choose the correct option out of the choices given below. Assertion (A): A molecule of SF ₄ is see-saw shaped, while that of CIF ₃ is T-shaped. Reason(R): SF₄ has two lone pair of electrons. But CIF₃ has one pair of electrons.
Options
- AAssertion (A) is correct but Reason (R) is incorrect
- BAssertion (A) and Reason (R) are correct
- CAssertion (A) is incorrect but Reason (R) is correct
- DBoth Assertion (A) and Reason (R) are incorrect
Correct answer
A. Assertion (A) is correct but Reason (R) is incorrect
Step-by-step solution
In SF ₄ , the central sulfur atom has 6 valence electrons. It forms 4 bonds with fluorine atoms, leaving 2 electrons, which constitute 1 lone pair. The steric number is 4 + 1 = 5 , corresponding to a trigonal bipyramidal electron geometry. With one lone pair in the equatorial position, the molecular geometry is see-saw shaped. Thus, the assertion regarding SF ₄ is correct, but the reason stating it has two lone pairs is incorrect. In CIF ₃ , the central chlorine atom has 7 valence electrons. It forms 3 bonds with f