Class NEET 2026 ALL Q #1956
COMPETENCY BASED
ANALYZE
4 Marks 2026 NTA-RE-NEET-2026 MCQ SINGLE
Given below are two statements: Statement-I: $[Fe(ox)_{3}]^{3-}$ is chiral. Statement-II: trans-$[Cr(H_{2}O)_{2}(ox)_{2}]^{-}$ is chiral. (Given: $oxH_{2}=HOOC-COOH$) In light of the above statements, choose the most appropriate answer from the options given below:
(A) Statement-I is incorrect but Statement-II is correct
(B) Both Statement-I and Statement-II are correct
(C) Both Statement-I and Statement-II are incorrect
(D) Statement-I is correct but Statement-II is incorrect
Correct Answer: D

AI Tutor Explanation

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Detailed Solution

Step 1: Analyze Statement-I

The complex $[Fe(ox)_{3}]^{3-}$ contains three bidentate oxalate ligands. This is a tris-chelated octahedral complex of the type $[M(AA)_{3}]$. Such complexes lack a plane of symmetry and a center of inversion, making them optically active (chiral). Therefore, Statement-I is correct.

Step 2: Analyze Statement-II

The complex trans-$[Cr(H_{2}O)_{2}(ox)_{2}]^{-}$ has two oxalate ligands and two water ligands in a trans configuration. In the trans isomer, the two water ligands are 180 degrees apart, and the two oxalate ligands lie in the same plane. This configuration possesses a plane of symmetry (and a center of inversion), which renders the molecule achiral (optically inactive). Therefore, Statement-II is incorrect.

Step 3: Conclusion

Since Statement-I is correct and Statement-II is incorrect, the correct option is (D).

Final Answer: Statement-I is correct but Statement-II is incorrect

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Pedagogical Audit
Bloom's Analysis: This is an ANALYZE question because the student must visualize the 3D geometry of coordination complexes and identify symmetry elements to determine chirality.
Knowledge Dimension: CONCEPTUAL
Justification: The question tests the understanding of stereoisomerism and symmetry principles in coordination chemistry rather than rote memorization of facts.
Syllabus Audit: In the context of NEET, this is classified as COMPETENCY. It requires the application of Crystal Field Theory and Isomerism concepts to solve a multi-statement problem typical of competitive entrance exams.