Select the diamagnetic coloured compound:

The magnetic moment (spin only) of $[NiCl_{4}]^{2-}$ is ....... $B.M.$

$[Co(NH_3)_4Cl_2]^+$ exhibits

In an experiment,$m$ grams of a compound $X$ (gas/liquid/solid) taken in a container is loaded in a balance as shown in figure $I$ below. In the presence of a magnetic field,the pan with $X$ is either deflected upwards (figure $II$),or deflected downwards (figure $III$),depending on the compound $X$. Identify the correct statement$(s)$:
$(A)$ If $X$ is $H_2O_{(l)}$,deflection of the pan is upwards.
$(B)$ If $X$ is $K_4[Fe(CN)_6]_{(s)}$,deflection of the pan is upwards.
$(C)$ If $X$ is $O_{2(g)}$,deflection of the pan is downwards.
$(D)$ If $X$ is $C_6H_{6(l)}$,deflection of the pan is downwards.

Identify the incorrect match from the following:

The total number of possible isomers for $[Pt(NH_3)_4Cl_2]Br_2$ is . . . . . . .