The solubility of $AgCl$ in $NH_4OH$ is due to the formation of:

Which of the following statements is incorrect?

The yellow compound $PbCrO_4$ dissolves upon treatment with a hot $NaOH$ solution. The lead-containing product formed is a:

Choose the correct statements from the following:
$A$. Ethane$-1, 2-$diamine is a chelating ligand.
$B$. Metallic aluminium is produced by electrolysis of aluminium oxide in the presence of cryolite.
$C$. Cyanide ion is used as a ligand for the leaching of silver.
$D$. Phosphine acts as a ligand in Wilkinson's catalyst.
$E$. The stability constants of $Ca^{2+}$ and $Mg^{2+}$ are similar with $EDTA$ complexes.
Choose the correct answer from the options given below:

Which of the following cations forms the least stable complex with the same ligand?

$AgCl$ dissolves in a solution of $NH_3$ but not in water because