Which compound does not dissolve in hot dilute $HNO_3$?

When $H_2S$ gas is passed through a solution,it reacts to form a white precipitate. Which ion is present in the solution?

$A$ metal nitrate reacts with $KI$ to give a black precipitate which on addition of excess of $KI$ converts into an orange-colored solution. The cation of the metal nitrate is

In the wet tests for identification of various cations by precipitation,which transition element cation does not belong to group $IV$ in qualitative inorganic analysis?

$A$ solution containing a group $IV$ cation gives a precipitate on passing $H_2S$ gas. $A$ solution of this precipitate in dilute $HCl$ produces a white precipitate with $NaOH$ solution and a bluish-white precipitate with basic potassium ferrocyanide. The cation is:

In qualitative analysis,in order to detect $II$ group basic radicals,$H_2S$ gas is passed in the presence of dilute $HCl$ to: