Which of the following reaction produces SO2 gas?Burning of sulphur in oxygenReaction of copper with H2SO4Roasting of sulphide oresBurning of H2S

All of the reactions mentioned can produce SO2 gas. Here's how:

1. Burning of sulphur in oxygen: When sulphur burns in oxygen, it produces sulphur dioxide (SO2). The reaction is as follows: S(s) + O2(g) → SO2(g)

2. Reaction of copper with H2SO4: When copper reacts with concentrated sulphuric acid, it produces SO2 gas, copper sulphate and water. The reaction is as follows: Cu(s) + 2H2SO4(conc) → CuSO4(aq) + SO2(g) + 2H2O(l)

3. Roasting of sulphide ores: Roasting is a process of heating sulphide ore to a high temperature in the presence of air. This process converts sulphide ore into oxide, and sulphur is released as sulphur dioxide. For example, the roasting of zinc sulphide can be represented as: 2ZnS(s) + 3O2(g) → 2ZnO(s) + 2SO2(g)

4. Burning of H2S: When hydrogen sulphide burns in the presence of oxygen, it produces sulphur dioxide and water. The reaction is as follows: 2H2S(g) + 3O2(g) → 2SO2(g) + 2H2O(g)

So, all of the reactions mentioned above produce SO2 gas.