When 16.8 g of white solid X were heated, 4.4 g of acid gas A, that turned lime water milky was driven off together with 1.8 g of a gas B which condensed to a colourless liquid.
The solid that remained, Y, dissolved in water to give an alkaline solution, which with excess barium chloride solution gave a white precipitate Z. The precipitate efferversced with acid giving off carbon dioxide. Identify A, B and Y and write down the equation for the thermal decomposition of X.
Explain the following in not more than two sentenses.
A solution of FeCl3 in water gives a brown precipitate on standing.
Compound A is a light green crystalline solid. It gives the following tests :
(i) It dissolves in dilute sulphuric acid. No gas is produced.
(ii) A drop of KMnO4 is added to the above solution. The pink colour disappears.
(iii) Compound A is heated strongly. Gases B and C, with pungent smell, come out. A brown residue D is left behind.
(iv) The gas mixture (B and C) is passed into a dichromate solution. The solution turns green.
(v) The green solution from step (iv) gives a white precipitate E with a solution of barium nitrate.
(vi) Residue D from step (iii) is heated on charcoal in a reducing flame. It gives a magnetic substance E.
Name the compounds A, B, C, D and E.