Reduction of the metal centre in aqueous permanganate ion involves

The total number of contributing structure showing hyper-conjugation (involving C-H bonds) for the following carbocation is _________.

Among the following, the number of compounds that can react with PCl₅ to given POCl₃ is _____________.

O₂, CO₂, SO₂, H₂O, H₂SO₄, P₄O₁₀

The volume (in mL) of 0.1 M AgNO₃ required for complete precipitation of chloride ions present in 30 mL of 0.01 M solution of $$[Cr{({H_2}O)_5}Cl]C{l_2}$$, as silver chloride is close to ____________.