What color does lead acetate give with $H_2S$?

$H_2S$ gas is passed through an acidified solution containing $Ag^+$,$Cu^{2+}$,and $Zn^{2+}$ ions. Which of these will form a precipitate?

Compound $A$ on borax bead test in reducing flame gives green colour bead. Compound $A$ on treatment with $H_2O_2$ followed by treatment with $Pb(OAc)_2$ gives yellow ppt. The metal ion in the compound $A$ is :

In the analysis of basic radicals,the group reagent $H_2S$ gas is generally used in which groups?

$A$ light greenish coloured salt was soluble in water. On passing $H_2S$ into the solution,a black precipitate was obtained which dissolved readily in $HCl$. The metal ion present is:

$A$ solution is prepared by mixing a concentrated solution of $Co(NO_3)_2$ with a concentrated solution of $NaNO_2$ in $50\%$ acetic acid. $A$ solution of a salt containing metal $M$ is added to the mixture,and a yellow precipitate is formed. Metal $M$ is: