$AgCl$ dissolves in ammonia solution giving

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

Which of the following complexes represents maximum stability?

Which of the following coordination compounds acts as a non-electrolyte in solution?

In ${K_4}[Fe(CN)_6]$,$Fe$ is in the form of

The number of moles of $NH_{3}$ that must be added to $2 \, L$ of $0.80 \, M \, AgNO_{3}$ in order to reduce the concentration of $Ag^{+}$ ions to $5.0 \times 10^{-8} \, M$ ($K_{\text{formation}}$ for $[Ag(NH_{3})_{2}]^{+} = 1.0 \times 10^{8}$) is ...... . (Nearest integer)
[Assume no volume change on adding $NH_{3}$ ]