Write the conditions to maximize the yield of H2SO4 by contact process.
Manufacturing of sulphuric acid via the contact process involves three steps:
(1) Burning of ores to form SO2
(2) Conversion of SO2 to SO3 using V2O5 as a catalyst
(3) Absorption of SO3 in H2SO4 to give oleum
The second step, i.e. conversion of SO2 to SO3 is the key step. Since this reaction is exothermic in nature and two moles of gaseous reactant give one mole of gaseous product. Thus, in accordance with Le Chatelier's principle, to obtain the maximum amount of SO3, low temperature and high pressure are required.