Which of the following is not correctly matched?

$Fe$ (finely powdered) $+ HCl(dil.) \to P + Q\uparrow$. Compound $P$ does not precipitate with:

$A$ colorless aqueous solution contains nitrates of two metals,$X$ and $Y$. When it was added to an aqueous solution of $NaCl$,a white precipitate was formed. This precipitate was found to be partly soluble in hot water to give a residue $P$ and a solution $Q$. The residue $P$ was soluble in aqueous $NH_3$ and also in excess sodium thiosulfate. The hot solution $Q$ gave a yellow precipitate with $KI$. The metals $X$ and $Y$,respectively,are

$A$ 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

Which ion is precipitated by the reagent $NH_4Cl$ and aqueous $NH_3$?

Sometimes yellow turbidity appears on passing $H_2S$ gas even in the absence of the second group radicals. This happens because