Which of the following compounds changes the color of an aqueous $FeCl_3$ solution?

In the group $III$ radicals,in place of $NH_4Cl$,which of the following can be used?

Among $Fe^{3+}$, $Pb^{2+}$, $Cu^{2+}$, and $Mn^{2+}$, identify the one that gets precipitated out while passing $H_2S$ gas in the presence of $NH_4OH$ as a group reagent. The highest possible oxidation state of the corresponding metal is:

Identify the inorganic sulphides that are yellow in colour $ : $
$(A)$ $(NH_4)_2S$
$(B)$ $PbS$
$(C)$ $CuS$
$(D)$ $As_2S_3$
$(E)$ $As_2S_5$
Choose the correct answer from the options given below $ : $

Compound $X$ is tested and the results are shown in the table.

Test	Result
Aqueous $NaOH$ is added, then heated gently.	Gas given off which turns damp red litmus paper blue.
Dilute $HCl$ is added.	Effervescence, gas given off which turns lime water milky and acidified $K_2Cr_2O_7$ paper green.

Which ions are present in compound $X$?

In which of the following is $NH_{3}$ not used?