use standard enthalpies of formation to calculate delta Hrxn for the following reaction. 2H2S(g)+3O2(g)-->2H2O(l)+2SO2(g) express the answer using four significant figures

Question

Delta Hrxn = ? kJ

Answer 1

ÄH°reaction = sum of standard enthalpy of formation of products - sum of standard enthalpy of formation of reactants
ÄH°reaction = [ 2 X ÄH°f for H2O + 2 X ÄH°f for SO2 ] - [ 2 X ÄH°f for H2S + 3 X ÄH°f for O2 ]
ÄH°reaction = [ 2 X -285.8 + 2 X -296.8 ] - [ 2 X -20.63 + 3 X 0 ]
ÄH°reaction = [-571.6 - 593.6 ] - (-41.26)
ÄH°reaction = -1165.2 + 41.26 = -1123.94 kj