Identify the cation [positive ion] and anion [negative ion] in - A, B and C. Also identify P, Q, R, S, T, U, V, W.

(a) Substance 'A' is water soluble and gives a curdy white precipitate 'P' with silver nitrate solution. 'P' is soluble in ammonium hydroxide but insoluble in dil. HNO₃. Substance 'A' reacts with ammonium hydroxide solution to give a white precipitate 'Q' soluble in excess of NH₄OH.

(b) A solution of substance 'B' is added to barium chloride solution. A white ppt. 'R' is formed, insoluble in dil. HCl or HNO₃. A dirty green ppt. 'S' is formed on addition of ammonium hydroxide to a solution of 'B' and the precipitate is insoluble in excess of ammonium hydroxide.

(c) Substance 'C' is a coloured, crystalline salt which on heating decomposes leaving a black residue 'T'. On addition of copper turnings and conc. H₂SO₄ to 'C' a coloured acidic gas 'U' is evolved on heating. A solution of 'C' is added to NaOH soln. until in excess. A pale blue ppt. 'P' is obtained insoluble in excess of NaOH. A solution of 'C' is then added to NH₄OH soln. in excess to give an inky blue solution 'V'. A solution of 'C' is warmed and hydrogen sulphide gas is passed through it. A black ppt. 'W' appears.

Match the 'cations' A to F and the solubility of ppt. G or H with the correct colours from 'X' and 'Y'.

Give balanced equations for the conversions A and B.

1. $\text{Metallic carbonate} \quad \raisebox{0.35em}{A} \space \xrightarrow{\text{Ba(NO}$3)2} \text{White precipitate} \quad \raisebox{0.35em}{B} \space \xrightarrow{\text{dil. HCl}} \text{precipitate dissolves}
2. $\text{Metallic sulphide} \quad \raisebox{0.35em}{A} \space \xrightarrow{\text{Pb(CH}$3{\text{COO}})2 \text{ soln.}} \text{black precipitate }
3. $\text{Metallic salt} \quad \raisebox{0.35em}{A} \space \xrightarrow{\text{BaCl}_2 \text{ soln.}} \text{Barium sulphite} \quad \raisebox{0.35em}{B} \space \xrightarrow{\text{dil. HCl}} \text{Barium chloride}$
4. $\text{Metallic chloride} \quad \raisebox{0.35em}{A} \space \xrightarrow{\text{conc. H}$2\text{SO}4\Delta} \text{Gas evolved} \quad \raisebox{0.35em}{B} \space \xrightarrow{\text{AgNO}_3} \text{White precipitate}
5. $\text{Metallic salt} \quad \raisebox{0.35em}{A} \space \xrightarrow{\text{BaCl}_2} \text{White precipitate insoluble in dil. HCl}$

Complete the table given below :