The octahedral complex $[Co(NH_3)_5SO_4]Cl$ exists in two isomeric forms $X$ and $Y$. Isomer $X$ reacts with $AgNO_3$ to give a white precipitate,but does not react with $BaCl_2$. Isomer $Y$ gives a white precipitate with $BaCl_2$ but does not react with $AgNO_3$. Isomers $X$ and $Y$ are $.....$

Which of the following complex ions will have a magnetic moment of $2.82 \ BM$?

The number of geometric isomers for the complex $[Co(NO_2)_2(NH_3)_2]$ is .....

$CoSO_{4}Cl \cdot 5NH_{3}$ exists in two isomeric forms '$A$' and '$B$'. Isomer '$A$' reacts with $AgNO_{3}$ to give white precipitate,but does not react with $BaCl_{2}$. Isomer '$B$' gives white precipitate with $BaCl_{2}$ but does not react with $AgNO_{3}$. Answer the following questions.
$(i)$ Identify '$A$' and '$B$' and write their structural formulas.
$(ii)$ Name the type of isomerism involved.
$(iii)$ Give the $IUPAC$ name of '$A$' and '$B$.'

The metal complex that is diamagnetic is (Atomic number: $Fe = 26, Cu = 29$)

The magnitude of magnetic moment (spin only) of $[NiCl_4]^{2-}$ will be ........ $B.M.$