Silica gel contains [Co(Cl₄)]²⁻ as an indicator. When activated, silica gel becomes dark blue while upon… · ABC26IN0096
Subject: Inorganic Chemistry · Chapter: Coordination Chemistry · Topic: Crystal Field Theory · Exam: CSIR NET 2013 · Marks: 2 · Difficulty: Medium
Silica gel contains $[\mathrm{Co(Cl_4)}]^{2-}$ as an indicator. When activated, silica gel becomes dark blue while upon absorption of moisture, its colour changes to pale pink This is because, [CSIR-JUNE 2013]
(a)Co(II) changes its coordination from tetrahedral to octahedral.
(b)Co(II) changes its oxidation state to Co(III)
(c)Tetrahedral crystal field splitting is NOT equal to octahedral crystal field splitting
(d)Co(II) forms kinetically labile while Co(III) forms kinetically inert complexes.