$A.$ $\left[ Fe ( CN )_6\right]^{3-}$;$B.$ $\left[ FeF _6\right]^{3-}$; $C.$ $\left[ CoF _6\right]^{3-}$; $D.$ $\left[ Cr (\text { oxalate })_3\right]^{3-}$; $E.$ $\left[ Ni ( CO )_4\right]$
નીચે આપેલા વિકલ્પોમાંથી સાચો જવાબ પસંદ કરો.
$B$. $\left[ FeF _6\right]^{3-} n =5$
$C$. $\left[ CoF _6\right]^{3-} n =4$
$D$. $\left.[\text { Cr(oxalate })_3\right]^{3-} n =3$
$E$. $\left[ Ni ( CO )_4\right] n =0$
$\left[\mathrm{V}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+},\left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+},\left[\mathrm{Fe}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+},\left[\mathrm{Ni}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+},\left[\mathrm{Cu}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}$
[ આપેલ પરમાણુ ક્રમાંક : $\mathrm{V}=23, \mathrm{Cr}=24, \mathrm{Fe}=26, \mathrm{Ni}=28 \mathrm{Cu}=29$ ]