NEETChemistryp Block Elements (Group 15, 16, 17 & 18)
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Nitrogen forms N ₂ O ₅ but does not form NCl ₅ . Reason (R): Nitrogen lacks vacant d-orbitals in its valence shell, restricting its maximum covalency to 4. In the light of the above statements, choose the correct answer from the options given below:
Options
- AAssertion (A) is true but Reason (R) is false.
- BAssertion (A) is false but Reason (R) is true.
- CBoth Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A).
- DBoth Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
Correct answer
D. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
Step-by-step solution
Assertion (A) is true: Nitrogen forms the pentoxide N ₂ O ₅ but cannot form the pentahalide NCl ₅ . Reason (R) is true and correctly explains (A): Nitrogen has only one s and three p orbitals in its valence shell, so its maximum covalency is restricted to 4. In N ₂ O ₅ , nitrogen exhibits a +5 oxidation state but its covalency does not exceed 4. However, to form NCl ₅ , nitrogen would need to form five single bonds, requiring a covalency of 5. Since it lacks vacant d-orbitals to expand its octet, NCl ₅ does not exi