The molar ionic conductances of the octahedral complexes are in the order of:
$(1) PtCl_4 \cdot 5NH_3$
$(2) PtCl_4 \cdot 4NH_3$
$(3) PtCl_4 \cdot 3NH_3$
$(4) PtCl_4 \cdot 2NH_3$

$A$ first row transition metal $(M)$ does not liberate $H_{2}$ gas from dilute $HCl$. $1 \ mol$ of aqueous solution of $MSO_{4}$ is treated with excess of aqueous $KCN$ and then $H_{2}S_{(g)}$ is passed through the solution. The amount of $MS$ (metal sulphide) formed from the above reaction is . . . . . . $mol$.

In the following reaction sequence in aqueous solution,the species $X, Y$ and $Z$,respectively,are

The overall stability constant of the complex ion $[Cu(NH_3)_4]^{2+}$ is $2.1 \times 10^{13}$. The overall dissociation constant is $y \times 10^{-14}$. Then $y$ is ....... .(Nearest integer)

The aqueous solution of a transition metal salt changes colour from pink to blue when concentrated hydrochloric acid is added to it. The change in colour is due to:

In $[Fe(CO)_5]$,the $Fe-C$ bond has