Identify the metal ions among $Co^{2+}, Ni^{2+}, Fe^{2+}, V^{3+}$ and $Ti^{2+}$ having a spin-only magnetic moment value more than $3.0 \ BM$. The sum of unpaired electrons present in the high spin octahedral complexes formed by those metal ions is . . . . . . .

Which of the following is incorrectly matched?
Complex $-$ Number of unpaired electrons

$Cis-trans$ isomerism is exhibited by

The magnetic moments of the complexes given below are in the order:
$I. [Ni(CO)_4]$
$II. [Mn(CN)_6]^{4-}$
$III. [Cr(NH_3)_6]^{3+}$
$IV. [CoF_6]^{3-}$

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.

Which of the following complex compounds will exhibit highest paramagnetic behaviour?
(At. No. $Ti = 22, Cr = 24, Co = 27, Zn = 30$)