The magnetic moments of following,arranged in decreasing order will be :-

$(i)$ $Co^{3+}$ (Octahedral complex with a strong field ligand)

$(ii)$ $Co^{3+}$  (Octahedral complex with a weak field ligand like $F^-$ )

$(iii)$ $Co^{2+}$  (Tetrahedral complex)

$(iv)$ $Co^{2+}$ (Square planar complex)

A pink colored salt on dry heating becomes blue in colour. Salt may contain 

Which one of the following characteristics of the transition metals is associated with their catalytic activity

Why first ionisation enthalpy of $\mathrm{Cr}$ is lower than that of $\mathrm{Zn}$ ?

Cuprous ion is colourless, while cupric ion is coloured because

Prussian blue is due to the formation of