Which of the following may be colourless

The purple colour of $KMnO_4$ is due to the transition

In a transition series, as the atomic number increases, paramagnetism

A first row transition metal in its $+2$ oxidation state has a spin-only magnetic moment value of $3.86 \mathrm{BM}$ The atomic number of the metal is

Why does copper not replace hydrogen from acids ?

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)