The isomer$(s)$ of $[Co(NH_{3})_{4}Cl_{2}]^{+}$ that has/have a $Cl-Co-Cl$ angle of $90^{\circ}$ is/are:

Which of the following pairs of isomers and their types of isomerism are correct? Select the correct option.
$(1)\ [Co(NH_3)_5(NO_2)]Cl_2$ and $[Co(NH_3)_5(ONO)]Cl_2$: Linkage isomerism
$(2)\ [Cu(NH_3)_4][PtCl_4]$ and $[Pt(NH_3)_4][CuCl_4]$: Coordination isomerism
$(3)\ [Pt(NH_3)_4Cl_2]Br_2$ and $[Pt(NH_3)_4Br_2]Cl_2$: Ionization isomerism

Which of the following complex ions will exhibit paramagnetic behavior?

Magnetic moment of $d^6$ low spin complex is ........ $B.M.$

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

List-$I$	List-$II$
$a. [Fe(CN)_{6}]^{3-}$	$i. 5.92 \ BM$
$b. [Fe(H_{2}O)_{6}]^{3+}$	$ii. 0 \ BM$
$c. [Fe(CN)_{6}]^{4-}$	$iii. 4.90 \ BM$
$d. [Fe(H_{2}O)_{6}]^{2+}$	$iv. 1.73 \ BM$

Choose the correct answer from the options given below.

Which of the following complexes has a zero magnetic moment (spin only)?