Which of the following will not give a precipitate with $AgNO_3$?

The correct increasing order of trans-effect of the following species is:

Which among the following cations forms the most stable complex with the same ligand?

What is the color of the aqueous solution of $[Co(NH_3)_6]^{3+}$?

Which one of the following metal complexes is most stable?

Which one is the most likely structure of $CrCl_3 \cdot 6H_2O$ if $1/3$ of total chlorine of the compound is precipitated by adding $AgNO_3$ to its aqueous solution?