The formula of the product formed, when sodium thiosulphate solution is added to silver bromide is

Which of the following ions forms the most stable complex compound?

$\pi$-acid ligands are

Compound $PdCl_4 \cdot 6H_2O$ is a hydrated complex; $1 \ m$ aqueous solution of it has a freezing point of $269.28 \ K$. Assuming $100\%$ ionization of the complex,calculate the molecular formula of the complex ($K_f$ for water $= 1.86 \ K \ kg \ mol^{-1}$,freezing point of pure water $= 273 \ K$).

$HgCl_2$ is a covalent compound,sparingly soluble in water. The solubility increases by the addition of chloride ions due to:

Assertion : $Cu^{2+}$ and $Cd^{2+}$ are separated from each other by first adding $KCN$ solution and then passing $H_2S$ gas.
Reason : $KCN$ reduces $Cu^{2+}$ to $Cu^{+}$ and forms a complex with it.