question_answer

\[\underset{Black}{\mathop{X\left( S \right)}}\,\xrightarrow{dil\,HCl}Y\uparrow \xrightarrow[NaOH]{N{{a}_{2}}\left[ Fe{{\left( CN \right)}_{5}}\left( NO \right) \right]}\] Purple solution gas Y has been allowed to react with following species in neutral/acidic medium:

(a) \[FeC{{l}_{3}}\]

(b) \[CuS{{O}_{4}}\]

(c) \[BaC{{l}_{2}}\]

(d) \[S{{O}_{2}}\]

(e) \[C{{r}_{2}}O_{7}^{2-}\]

(f) \[C{{H}_{3}}COONa\]

(g) \[Hg_{2}^{2+}\]

Then calculate value of \[\left( P+Q-R \right)\]

P: Number of species which undergoes redox reaction with gas Y.

Q: Number of species with which gas Y undergoes precipitation.

R: Number of species with which gas Y produce no observable change.

Answer:

4.00