Read the following short write up and answer subsequent questions based on observations(A) to (J). [ β Qualitative and Quantitative Analysis Chemistry Question
Question
Read the following short write up and answer subsequent questions based on observations(A) to (J). [SEE DIAGRAM] Flowchart summary: AgNO3 -> white ppt. soluble in aq. NH3 + green coloured solution of a compound (A) green coloured solution of a compound (A) --(NaOH in excess)--> coloured ppt. soluble in excess NaOH green coloured solution of a compound (A) --(KOH/H2O2)--> yellow coloured solution (B) yellow coloured solution (B) --(H2SO4)--> orange coloured solution (C) orange coloured solution (C) --(NH4Cl)--> orange coloured solution of compound (D) --(Crystallization, Ξ)--> gas (G) + H2O + Residue (H) gas (G) --(Li, Ξ)--> solid (I) --(H2O)--> gas (J) --(CuSO4(aq))--> deep blue solution (C) in solid state --(KCl + conc. H2SO4)--> red gas (E) --(KOH(aq))--> (B) --(CH3COOH/Pb2+)--> yellow ppt. (F)
π‘ Solution & Explanation
Step 1: The reaction of bismuth(III) ions with iodide ions (I-) initially forms a dark brown/black precipitate of bismuth(III) iodide (BiI3). Step 2: The black BiI3 precipitate reacts with excess iodide ions to form a highly stable, soluble tetraiodobismuthate(III) complex anion: BiI3 + I- -> [BiI4]-. Step 3: The [BiI4]- complex solution exhibits a characteristic orange/yellow-orange color. This confirms the presence of Bi3+, matching option (b).