White precipitate of $AgCl$ dissolves in aqueous ammonia solution due to formation of $.....$ .

The aqueous solution of which of the following complexes has the least conductivity under identical conditions?

The stepwise stability constants of a complex are given below. What is its overall reaction stability constant $\beta_4$ ?
$M + L \rightleftharpoons ML ; K_1 = 1.0 \times 10^4$
$ML + L \rightleftharpoons ML_2 ; K_2 = 1.0 \times 10^3$
$ML_2 + L \rightleftharpoons ML_3 ; K_3 = 1.0 \times 10^3$
$ML_3 + L \rightleftharpoons ML_4 ; K_4 = 1.0 \times 10^2$
(Overall reaction : $M + 4L \rightleftharpoons ML_4$)

Copper sulphate solution reacts with $KCN$ to give

Which one will give $Fe^{3+}$ ions in solution?

Identify the ligand with the lowest field strength among the following.