Sulphur trioxide gas is an important precursor to manufacture sulphuric acid. It is produced by the catalytic oxidation of SO2 gas. Which of the following are suitable catalysts for the process?
Sulphur trioxide gas is an important precursor to manufacture sulphuric acid. It is produced by the catalytic oxidation of SO2 gas. Which of the following are suitable catalysts for the process?
The correct option is D V2O5
2 SO2(g)+O2(g)⇌2SO3(g):ΔH=−197kJ.mol−1
In the contact process for the manufacture of Sulphuric acid, V2O5 is the preferred catalyst for the above reaction. Earlier, platinated asbestos was used. As can be seen from the above equation, the enthalpy change is negative which implies that the reaction should be favoured in the forward direction for lower temperatures. However, in real scenarios a lower temperature could bring down the rate of the oxidation to unfeasible levels. So we don’t mind conducting the reaction at 450∘C and 1-2 atm pressure. Do note that the catalyst only accelerates the rate of the reaction without altering the position of the chemical equilibrium.
First the V5+ ions oxidize SO2 (g) into SO3 (g) and themselves get reduced to V4+ ions. Naturally the doubt arises as to whether this involvement of Vanadium ions affects the equilibrium. Through catalyst regeneration, the V4+ ions are oxidized back to V5+ ions such that Vanadium ions are not part of the overall reaction!
V2O5
2 SO2(g)+O2(g)⇌2SO3(g):ΔH=−197kJ.mol−1
In the contact process for the manufacture of Sulphuric acid, V2O5 is the preferred catalyst for the above reaction. Earlier, platinated asbestos was used. As can be seen from the above equation, the enthalpy change is negative which implies that the reaction should be favoured in the forward direction for lower temperatures. However, in real scenarios a lower temperature could bring down the rate of the oxidation to unfeasible levels. So we don’t mind conducting the reaction at 450∘C and 1-2 atm pressure. Do note that the catalyst only accelerates the rate of the reaction without altering the position of the chemical equilibrium.
First the V5+ ions oxidize SO2 (g) into SO3 (g) and themselves get reduced to V4+ ions. Naturally the doubt arises as to whether this involvement of Vanadium ions affects the equilibrium. Through catalyst regeneration, the V4+ ions are oxidized back to V5+ ions such that Vanadium ions are not part of the overall reaction!
