| List -I | List-II | ||
| A | Kaolinite | I | FeCO3 |
| B | Siderite | II | ZnCO3 |
| C | Malachite | III | [AL2(OH)4Si2 O5] |
| D | Colamine | IV | CuCO3.Cu(OH)2) |
Study the reaction scheme shown below and identify the reactants A, B and C. 
Study the reaction given below and answer the questions that follow:
NaNO₃ + H₂SO₄ → NaHSO₄ + HNO₃ (below 200°C)
(a) Give one reason for maintaining the temperature below 200°C.
(b) Why is concentrated Sulphuric acid used in the above reaction?