Question

Which of the following source materials generate \(SO_2\) that is used in contact process?

• A. \(S,\ FeS_2\)
• B. \(S,\ FeS\)
• C. \(H_2S,\ FeS_2\)
• D. \(Na_2S,\ FeS_2\)

Hint:

In the contact process, \(SO_2\) is mainly obtained by burning sulphur or roasting iron pyrites \((FeS_2)\).

Answer 1

The Correct Option is A

Step 1: Recall the contact process.
The contact process manufactures \( H_2SO_4 \). The first step is generating \( SO_2 \), which is then catalytically oxidised to \( SO_3 \) and absorbed in water.
Step 2: Elemental sulphur as a source.
Burning sulphur in air: \[ S + O_2 \rightarrow SO_2 \] Elemental sulphur is a valid industrial source of \( SO_2 \).
Step 3: Iron pyrite as a source.
Roasting iron pyrite in air: \[ 4FeS_2 + 11O_2 \rightarrow 2Fe_2O_3 + 8SO_2 \] \( FeS_2 \) is the primary industrial raw material for \( SO_2 \) production.
Step 4: Check other options.
FeS is not a standard industrial raw material. \( H_2S \) and \( Na_2S \) are not used industrially to produce \( SO_2 \) for the contact process.
Step 5: Identify the correct pair.
The industrial sources are elemental sulphur S and iron pyrite \( FeS_2 \), which is option 1.
Step 6: Confirm the answer.
\[ \boxed{S, \ FeS_2} \]