Read the following short write up and answer subsequent questions based on observations(A) to (J). [ — 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, Δ)--> gas (G) + H2O + Residue (H) gas (G) --(Li, Δ)--> 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)
💡 Solution & Explanation
CrCl3 with AgNO3 gives AgCl (white ppt) and Cr3+. Cr3+ with NaOH gives Cr(OH)3 (green) which dissolves in excess NaOH to form [Cr(OH)4]-. Cr3+ is oxidized by H2O2/KOH to CrO4^2- (yellow solution, B).