The number of terminal oxygen atoms present in the product B obtained from the following reaction is _____________.

FeCr₂O₄ + Na₂CO₃ + O₂ $$\to$$ A + Fe₂O₃ + CO₂

A + H⁺ $$\to$$ B + H₂O + Na⁺

An acidified manganate solution undergoes disproportionation reaction. The spin-only magnetic moment value of the product having manganese in higher oxidation state is _____________ B.M. (Nearest integer)

The number of statements correct from the following for Copper (at. no. 29) is/are ____________.

(A) Cu(II) complexes are always paramagnetic.

(B) Cu(I) complexes are generally colourless

(C) Cu(I) is easily oxidized

(D) In Fehling solution, the active reagent has Cu(I)

The spin-only magnetic moment value of the most basic oxide of vanadium among V₂O₃, V₂O₄ and V₂O₅ is _____________ B.M. (Nearest integer)