MHT CET Chemistry Question (2026) — Solution

Step-by-step solution

The effective atomic number (EAN) is calculated using the formula: EAN = Z - O.S. + 2 C.N. For the complex [ Co ( NH _3)_6]^ 3+ , the central metal is cobalt. Atomic number of Co (Z) = 27 Oxidation state of Co ( O.S. ) = +3 Coordination number ( C.N. ) = 6 Substituting the values into the formula: EAN = 27 - 3 + 2 6 EAN = 24 + 12 = 36 Answer: 36