$\mu = \sqrt{15}$ is true for the pair :-
$Co^{+2}, Cr^{+3}$
$Fe^{+2}, Cr^{+3}$
$Fe^{+3}, Fe^{+2}$
$Mn^{+2} , Fe^{+2}$
On heating $Mn{(OH)_2}$ with $Pb{O_2}$ and conc. $HN{O_3}$ pink colour is obtained due to the formation of
Steel differs from pig iron and wrought iron in that it contains
A pink coloured salt turns blue on heating. The presence of which cation is most likely ?
Most stable cation in aqueous medium is
Spiegeleisen is an alloy of