Which of the following complexes is octahedral,diamagnetic,and the most stable?

The $CN^-$ ion exhibits which of the following properties towards metal components: $(a)$ Reducing agent,$(b)$ Oxidizing agent,$(c)$ Complexing agent?

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

Cobalt$(III)$ chloride forms a green coloured complex '$X$' with $NH_3$. The number of moles of $AgCl$ formed when an excess of $AgNO_3$ solution is added to $100 \ mL$ of a $1 \ M$ solution of '$X$' is:

The stability constants for complexes formed by a metal ion $(M^{2+})$ with ligands $NH_3$,$CN^-$,$H_2O$,and $en$ are $10^{11}$,$10^{27}$,$10^{15}$,and $10^8$ respectively. Based on these values,which of the following is correct?

Which of the following represents the correct increasing order of the spectrochemical series (field strength) for some common ligands?