1)C(s)+O2(g)===CO2(g) △H1=﹣393.5kJ·mol-1
2)2H2(g)+O2(g)===2H2O(g) △H2=﹣483.6kJ·mol-1
3)C(s)+H2O(g)===CO(g)+H2(g) △H3= +131.3kJ·mol-1
把1 式-3式得
C(s)+O2(g)-[C(s)+H2O(g)]=CO2(g)-[CO(g)+H2(g) ]
O2(g)-H2O(g)==CO2(g)-[CO(g)+H2(g) ]
CO(g)+H2(g)+O2(g)==CO2(g)+H2O(g)
△H=△H1-△H3=-395-131.3=-526.3KJ/mol
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