In: Chemistry
Calculate ΔH∘ in kilojoules for the reaction of
acetylene (C2H2) (ΔH∘f=227.4kJ/mol) with O2 to yield
carbon dioxide (CO2)(ΔH∘f=−393.5 kJ/mol) and
H2O(g) (ΔH∘f=−241.8kJ/mol), a reaction which is
supplied by the industrial gases industry for oxyacetylene gas
welding and cutting due to the high temperature of the flame.
2C2H2(g)+5O2(g)→4CO2(g)+2H2O(g)
Express your answer using one decimal place.
fH0 C2H2 = 227.4 KJ/mol
fH0 O2(g) = 0 KJ/mol
fH0 CO2(g) = -393.5 KJ/mol
fH0 H2O(g) = -241.8 KJ/mol
H0 = fH0 (Product) - fH0 (Reactant)
H0 = [(4fH0 CO2) + (2fH0 H2O)] - [(2fH0 C2H2) + (5fH0 O2)]
= [(4 (-393.5)) + (2 (-241.8))] - [2(227.4) + (5 (0)]
= [-2057.6] - [454.8]
H0 = -2512.4 KJ/mol
H0 for reaction = -2512.4 KJ/mol