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已知CH4(g)+H2O(g)═CO(g)+3H2(g)△H=+206kJ/molCH4(g)+CO2(g)═2CO(g)+2H2(g)△H=+247kJ/molC-H键的键能约为413kJ/mol,O-H键的键能约为463kJ/mol,H-H键的键能约为436kJ/mol,则CO2中C=O键的键能

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已知CH4(g)+H2O(g)═CO(g)+3H2(g)△H=+206kJ/mol
CH4(g)+CO2(g)═2CO(g)+2H2 (g)△H=+247kJ/mol
C-H键的键能约为413kJ/mol,O-H键的键能约为463kJ/mol,H-H键的键能约为436kJ/mol,则CO2中C=O键的键能约为(  )

A. 797.5 kJ/mol

B. 900.5 kJ/mol

C. 962.5 kJ/mol

D. 1595 kJ/mol

▼优质解答
答案和解析
①CH4(g)+H2O(g)═CO(g)+3H2(g)△H=+206kJ/mol
②CH4(g)+CO2(g)═2CO(g)+2H2 (g)△H=+247kJ/mol
依据盖斯定律①×2-②得到:CH4(g)+2H2O(g)═CO2(g)+4H2(g)△H=+165kJ/mol
设C=O键的键能为xkJ/mol,
+165=413×4+463×4-C=2x-436×4
解得:x=797.5
故选:A.
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