(i) An inorganic iodide (A) on heating with a solution of KOH gives a gas (B) and the solution of a compound( C). (ii) The gas (B) on ignition in air gives a compound (D) and water. (iii) Copper sulphate forms a black precipitate on passing (B) through its solution. (iv) A precepitate of compound (E) is formed on reaction of (C) with copper sulphate solution. Identify (A) to (E) and give chemical equations for reactions at steps (i) to (iv).

(i) An inorganic iodide (A) on heating with a solution of KOH gives a

1.	(i) An inorganic iodide (A) on heating with a solution of KOH gives a gas (B) and the solution of a compound( C). (ii) The gas (B) on ignition in air gives a compound (D) and water. (iii) Copper sulphate forms a black precipitate on passing (B) through its solution. (iv) A precepitate of compound (E) is formed on reaction of (C) with copper sulphate solution. Identify (A) to (E) and give chemical equations for reactions at steps (i) to (iv).
Answer» Solution :GAS (B) when passed through copper sulphate solution reduces the latter to copper metal, this indicates that the gas (B) is phosphine `(PH_(3))`. Thus the inorganic iodide must be phosphonium iodide `(PH_(4)l)`. The various reactions can be written as below: (i) `PH_(4)l + KOH to UNDERSET(B)(PH_(3)) + underset(C)(Kl) + H_(2)O` (ii) `underset("B")(2PH_(3)) + 4O_(2) to underset("D")(P_(2)O_(5)) + 3H_(2)O` (iii) `3CuSO_(4) + 2PH_(3) to Cu_(2)P_(2) + 3H_(2)SO_(4)` (IV) `2CuSO_(4) + 4Kl to Cu_(2)I_(2) darr + 2K_(2)SO_(4) + I_(2)`