An inorganic halide `(A)` reacts with water to form two acids `(B)` and `(c). (A)` also reacts with `NaOH` to form two salts `(D)` and `( E)` which remain in solution. The solution gives white precipitate with both `AgNO_3` and `BaCl_2` solutions respectively. `(A)` is a useful organic reagent. Identify `(A)` to `( E)`.

An element E reacts with water to form a solution which turns phenolphthalein solution pink. The element E is most likely to be:

Colourless salt (A) decolourise I_(2) solution and gives white precipitate (change to black) with AgNO_(3) solution. (A) also produces pink colour with FeCl_(3) solution. Identify (A) and explain reactions.

A white substance (A) reacts with dilute H_(2)SO_(4) to produce a colourless suffocating gas (B) and a colourless solution (C )/ The reaction of gas (B) with potassium iodate and starch solution produce a blue colour solution. Aqueous Solution of (A) gives a white precipitate with BaCl_(2) solution which is soluble in dilute HCl . Addition of aqueous NH_(3) or NaOH to (C ) produced first a precipitate which dissolves in excess of the respective reagent to poduced a clear solution. Similarly addition of excess of potassium ferrocyanide to (C ) produced a precipitate (D) which also dissolves in aqeous NaOH giving a clear solution. Identify (A),(B),(C ) and (D ). Write the equation of the reactions involved.

A white substance (A) reacts with dilute H_(2)SO_(4) to produce a colourless suffocating gas (B) and a colourless solution (C )/ The reaction of gas (B) with potassium iodate and starch solution produce a blue colour solution. Aqueous Solution of (A) gives a white precipitate with BaCl_(2) solution which is soluble in dilute HCl . Addition of aqueous NH_(3) or NaOH to (C ) produced first a precipitate which dissolves in excess of the respective reagent to poduced a clear solution. Similarly addition of excess of potassium ferrocyanide to (C ) produced a precipitate (D) which also dissolves in aqeous NaOH giving a clear solution. Identify (A),(B),(C ) and (D ). Write the equation of the reactions involved.