Sulphur trioxide can be obtained by which of the following reactions:

Options

A. `CaSO_(4)+C overset(Delta)rarr`
B. `Fe_(2)(SO_(4))_(3) overset(Delta)(rarr)`
C. `S+H_(2)SO_(4) overset(Delta)rarr`
D. `H_(2)SO_(4)+PCl_(5)rarr`

Answer

2

Explanation

Heating ferric sulphate strongly
`Fe_(2)(SO_(4))_(3) overset(Delta)(rarr) Fe_(2)O_(3)+SO_(3)`
Other reactions are
`2CaSO_(4)+C overset(Delta)(rarr) 2CaO+2SO_(2)+CO_(2)`
`S+H_(2)SO_(4) overset(Delta)(rarr) 2H_(2)O+SO_(2)`
`H_(2)SO_(4)+PCl_(5) rarr HO-SO_(2)-Cl+POCl_(3)+HCl`
`HO-SO_(2)-Cl overset(PCl_(5))(rarr) Cl-SO_(2)-Cl +POCl_(3)+HCl`