NEETChemistryd and f Block Elements
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): On heating KMnO ₄ at 513 K , the major green-colored product obtained is paramagnetic in nature. Reason (R): The thermal decomposition of KMnO ₄ produces K ₂ MnO ₄ , in which manganese is in the +6 oxidation state with one unpaired d -electron. In the light of the above statements, choose the most
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
A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A)
Step-by-step solution
When potassium permanganate ( KMnO ₄ ) is heated at 513 K , it decomposes as follows: 2 KMnO ₄ 513 K K ₂ MnO ₄ + MnO ₂ + O ₂ The major green-colored product formed is potassium manganate ( K ₂ MnO ₄ ). In K ₂ MnO ₄ , the oxidation state of manganese is +6 . The electronic configuration of Mn ⁶⁺ is [ Ar ] 3d^1 . Since it contains one unpaired electron in its d -orbital, K ₂ MnO ₄ is paramagnetic in nature. Thus, Assertion (A) is true. Reason (R) correctly identifies the green product as K ₂ MnO ₄ and explains its pa