The number of species having a square planar shape from the following is $........$.
$XeF_4$,$SF_4$,$SiF_4$,$BF_4^{-}$,$BrF_4^{-}$,$[Cu(NH_3)_4]^{2+}$,$[FeCl_4]^{2-}$,$[PtCl_4]^{2-}$

Select the incorrect statement.

Sulphide ions react with sodium nitroprusside in a basic medium giving a coloured solution. In the reaction,the oxidation state of iron:

Which of the following is a low spin complex?

Give the correct order of initials $T$ or $F$ for following statements. Use $T$ if statement is true and $F$ if it is false.
$(I)$ Sulphide ions react with $Na_2[Fe(CN)_5(NO)]$ to form a purple coloured compound $Na_4[Fe(CN)_5(NOS)]$. In the reaction,the oxidation state of iron changes.
$(II)$ $Pt(IV)$ compounds are relatively more stable than $Ni(IV)$ compounds.
$(III)$ The welding of magnesium can be done in the atmosphere of Helium.
$(IV)$ $LiAlH_4$ on hydrolysis will give $H_2$.

The number of ions present in $2.0 \ L$ of a solution of $0.8 \ M \ K_4[Fe(CN)_6]$ is