The total number of stereoisomers for the complex $$\left[\mathrm{Cr}(o x)_{2} \mathrm{ClBr}\right]^{3-}$$ (where $$o x=$$ oxalate) is :

The major product for the following reaction is:

The naturally occurring amino acid that contains only one basic functional group in its chemical structure is

Which of the following complexes will exhibit maximum attraction to an applied magnetic field?