76.0 kJ, According to the provided reaction and stoichiometry, 76.0 kJ of heat will be emitted when 8.21 g of sulphur interacts with too much oxygen to create sulphur dioxide.
We must first determine how many moles of sulphur are present:
S mass divided by S's molar mass equals moles of S.
8.21 g/32.06 g/mol = 0.256 mol are the moles of sulphur.
We may infer that all of the sulphur will react because there is an excess of oxygen, hence the reaction will result in:
1 mol SO2 divided by 0.256 mol S results in 0.256 mol SO2.
q = nΔH
where n is the number of moles of the product (SO2), q is the quantity of heat released, and H is the reaction's enthalpy change.
q = (0.128 mol)(-296.8 kJ/mol) = -76.0 kJ