Question

Describe the industrial manufacture of sulphur dioxide gas. Give also chemical equations of the reactions. Give chemical equations of the reactions of sulphuric acid with calcium fluoride, copper and sulphur.

Hint:

SO\(_2\) is mainly obtained by roasting metal sulphides in industry, and conc. H\(_2\)SO\(_4\) acts as a dehydrating & oxidising agent.

Answer 1

Step 1: Manufacture of SO\(_2\).
SO\(_2\) is produced by burning sulphur or roasting metal sulphides in air/oxygen.
Step 2: Important reactions.
\[ 2ZnS + 3O_2 \rightarrow 2ZnO + 2SO_2 \uparrow \] \[ 4FeS_2 + 11O_2 \rightarrow 2Fe_2O_3 + 8SO_2 \uparrow \] Step 3: Reactions of H\(_2\)SO\(_4\).
\[ CaF_2 + H_2SO_4 \rightarrow CaSO_4 + 2HF \uparrow \] \[ Cu + 2H_2SO_4 \, (conc.) \rightarrow CuSO_4 + SO_2 \uparrow + 2H_2O \] \[ S + 2H_2SO_4 \, (conc.) \rightarrow 3SO_2 \uparrow + 2H_2O \] Step 4: Conclusion.
SO\(_2\) is industrially produced by roasting sulphides, and conc. H\(_2\)SO\(_4\) liberates gases from CaF\(_2\), Cu, and S.