For the following reactions, the metal complexes X and Y are
(i) $Ni\left(s\right)\underset{1atm,25C}{\overset{CO\left(g\right)}{\to }}X$
(ii) $FeC{1}_2\stackrel{2Na{C}_5{H}_5}{\to }Y$
X and Y are respectively

Q. From the following given pairs containing co-ordination complex and the hybridisation of transition metal, the correct pair(s) is/are

I – $\left[Co\right(N{H}_3{)}_6{]}^{3+}–s{p}^3{d}^2$
II – $\left[Ni\right(CO{)}_4]–s{p}^3$
III – $[NiC{l}_4{]}^{2–}–s{p}^3$
IV – $\left[Co\right(C_2{O}_4){]}^{3–}–d^{2}s{p}^3$

Q. The number of geometrical isomers found in the metal complexes $\left[Pt\right(Cl{)}_2\left(N{H}_3{)}_2\right],\left[Ni\right(CO{)}_4],[Ru\left(H_{2}O{)}_{3}C{l}_3\right]\text{and}\left[CoC{l}_2\right(N{H}_3{)}_4{]}^{+}$ respectively, are

Q. $Ni(CO{)}_4$

Q. The geometry and magnetic behaviour of the complex $\left[Ni\right(CO{)}_4]$ are ______.

Q. Among $\left[NiC{l}_2\right(PP{h}_3{)}_2],[Ni\left(DMG{)}_2\right]$ and $\left[Ni\right(CO{)}_4]$ complexes, the hybridisation states of $Ni$ atoms are respectively :