Based on the flowchart, identify solid A, an impurity removed, explain why impurities must be removed, and write chemical equations for reactions in the catalytic chamber and diluter.

Here are the answers to the questions based on the flow chart:

b) i) Solid A is Sulfur.

b) ii) One impurity removed by the purifier is dust (or arsenic compounds).

b) iii) It is necessary to remove impurities because they can poison the catalyst in the catalytic chamber, reducing its efficiency or making it inactive.

b) iv) Write chemical equations for the reactions which occur in one:

• I Catalytic chamber. $$2SO_2(g) + O_2(g) \xrightarrow{V_2O_5} 2SO_3(g)$$
• II Diluter. $$H_2S_2O_7(l) + H_2O(l) \longrightarrow 2H_2SO_4(l)$$