Question

Calculate the enthalpy for the combustion reaction of sulfur to produce sulfur triaxide using the enthalpies of the two reactions shown below: 25(s) 302(g)→2503(g) ΔΗ =

Answer 1

The enthalpy for the combustion reaction of sulfur to produce sulfur trioxide is -1017 kJ/mol.

To calculate the enthalpy for the combustion reaction of sulfur to produce sulfur trioxide, we can use the given enthalpies of the two reactions. The reactions are:

S(s) + 3O2(g) → SO3(g) + O2(g) ΔH1 = -394 kJ/mol

SO3(g) + H2(g) + 3/2O2(g) → 2SO4(g) + H2O(l) ΔH2 = -1411 kJ/mol

Since the second reaction is the combustion of sulfur dioxide to produce sulfuric acid and water, we can use the enthalpy change for this reaction. However, we need to add the enthalpy of formation for sulfur dioxide to find the enthalpy for the combustion of sulfur. The enthalpy of formation for sulfur dioxide is given by:

ΔHf(SO3) = -394 kJ/mol (from reaction 1)

Now, we can calculate the enthalpy for the combustion of sulfur:

ΔH(S + O2 → SO3 + O2) = ΔH2 - ΔHf(SO3) = -1411 kJ/mol - (-394 kJ/mol) = -1017 kJ/mol

Therefore, the enthalpy for the combustion reaction of sulfur to produce sulfur trioxide is -1017 kJ/mol.