Which of the following will show optical isomerism?
$I$. $\text{Cis}-[Co(NH_3)_2(en)_2]^{3+}$
$II$. $\text{Trans}-[IrCl_2(C_2O_4)_2]^{3-}$
$III$. $[Rh(en)_3]^{3+}$
$IV$. $\text{Cis}-[Ir(H_2O)_3Cl_3]$

Which of the following compounds does not exhibit paramagnetism?

Which of the following pairs will have the same value of magnetic moment?

Increasing order of magnetic moments of $I. [Fe(CN)_6]^{4-}$,$II. [Fe(CN)_6]^{3-}$,$III. [Cr(NH_3)_6]^{3+}$,$IV. [Ni(H_2O)_4]^{2+}$ 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 '$B$.'

Match List-$I$ with List-$II$.

List-$I$ (Complex)	List-$II$ (Spin only magnetic moment in $B$.$M$.)
$A$. $[Cr(NH_3)_6]^{3+}$	$I$. $4.90$
$B$. $[NiCl_4]^{2-}$	$II$. $3.87$
$C$. $[CoF_6]^{3-}$	$III$. $0.0$
$D$. $[Ni(CN)_4]^{2-}$	$IV$. $2.83$

Choose the correct answer from the options given below: