MHT CET Chemistry Question (2026) — Solution

Step-by-step solution

The coordination complex is Potassium hexacyanoferrate(II), which is K_4[Fe(CN)_6]. The central metal ion is Fe^ 2+ and the ligands are CN^ - ions. In the formation of a coordination complex, the central metal ion accepts electron pairs from the ligands to form coordinate covalent bonds. According to the Lewis acid-base theory, an electron pair acceptor is a Lewis acid. Therefore, the central atom/ion acts as a Lewis acid. Answer: Lewis acid