I have started learning Qualitative Salt analysis recently. When I was reading about tests to distinguish $\ce{CO3^2-}$ and $\ce{HCO3-}$, I came across a line in a book which states
$\ce{HgCl2}$ forms a reddish-brown precipitate of $\ce{3HgO.HgCO3}$ with $\ce{HCO3-}$ but no reaction is reported in case of $\ce{CO3^2-}$.
I am not able to understand why there will be no reaction of $\ce{HgCl2}$ with $\ce{CO3^2-}$.
It would be better if I can get a sound logic for this so that I can remember it better.