A-LevelChemistryEquilibriaMay/June 2025Paper 1 Q41 Mark
The reaction between sulfur dioxide and oxygen has the equation shown. 2SO2(g) + O2(g) ⇌ 2SO3(g) ΔH = –197 kJ mol⁻¹ 1.0 mol of SO2 and 1.0 mol of O2 are placed in a closed container and heated to a constant temperature. At this temperature, 0.8 mol of SO3 are present in the equilibrium mixture. Which statement is correct?
AThe equilibrium partial pressure of SO2 is greater than the equilibrium partial pressure of O2.
BKp has units of mol dm⁻³.
CAt a lower temperature, the equilibrium amount of SO3 is lower than 0.8 mol.
DThe mole fraction of SO3 is less than 0.8.
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