Find the compound ‘\( A \)’ from the following reaction sequences.\( \text{A} \xrightarrow{\text{aqua-regia}} \text{B} \xrightarrow[(2)\text{AcOH}]{(1)\text{KNO}_2/\text{NH}_4\text{OH}} \text{yellow ppt}\)
\( \mathrm{MnS} \)
\( \mathrm{ZnS} \)
\( \mathrm{NiS} \)
\( \mathrm{CoS} \)
Among the following cations, the number of cations which will give characteristic precipitate in their identification tests with \( \mathrm{K_4[Fe(CN)_6]} \) is ________.\( \mathrm{Cu^{2+},\ Fe^{3+},\ Ba^{2+},\ Ca^{2+},\ NH_4^{+},\ Mg^{2+},\ Zn^{2+}} \)
Identify the inorganic sulphides that are yellow in colour:(A) \( (\mathrm{NH}_4)_2\mathrm{S} \)(B) \( \mathrm{PbS} \)(C) \( \mathrm{CuS} \)(D) \( \mathrm{As}_2\mathrm{S}_3 \)(E) \( \mathrm{As}_2\mathrm{S}_5 \)Choose the correct answer from the options given below:
