Govt Exams
Be²⁺ has the smallest size and highest charge density, making it the strongest Lewis acid. It undergoes extensive hydrolysis. The order is Be²⁺ > Al³⁺ > Mg²⁺ > Ba²⁺.
Rapid mixing increases collision frequency. The presence of AgCl seed crystal provides nucleation sites. Both factors enhance precipitation rate by different mechanisms.
Pt²⁺ is d⁸ with strong field Cl⁻ ligands. The dsp² hybridization gives square planar geometry, which is the preferred geometry for d⁸ complexes with strong field ligands.
Both MnO₂ and Pt catalyze H₂O₂ decomposition to H₂O and O₂. MnO₂ is a heterogeneous catalyst while Pt can function as both heterogeneous and homogeneous catalyst.
SiCl₄ is most covalent due to small Si⁴⁺ size and high charge density. Covalent character increases: NaCl < MgCl₂ < AlCl₃ < SiCl₄.
Fe²⁺ has d⁶ configuration. In octahedral geometry with weak field ligand H₂O, it remains high spin with 4 unpaired electrons giving μ = √[4(4+2)] ≈ 4.90 BM, but aqua complex shows ~5.92 BM.
Manganese with lower electron density shows weaker back-bonding, resulting in higher CO stretching frequency. The order is Mn > Co > Fe > Ni based on back-bonding strength.
Tungsten forms the most stable +6 oxidation state compounds like WO₃ and WCl₆. The stability of +6 state decreases from W to Mo to Cr due to increasing ease of reduction.
Crystal field splitting depends on ligand strength, metal ion charge, and geometry, but NOT on the mass of the metal ion.
MnO₂ (Mn⁴⁺) acts as oxidizing agent, reducing Cl⁻ to Cl₂. Mn⁴⁺ gains 2 electrons, reducing to Mn²⁺.