Some mean bond enthalpies are shown in the table below:
| Bond | Mean bond enthalpy / kJ mol−1\text{kJ mol}^{-1}kJ mol−1 |
|---|---|
| C-H\text{C-H}C-H | 413 |
| C-O\text{C-O}C-O | 358 |
| C=O\text{C=O}C=O | 805 |
| O-H\text{O-H}O-H | 464 |
| O=O\text{O=O}O=O | 498 |
What is the enthalpy change, in kJ mol−1\text{kJ mol}^{-1}kJ mol−1, for the complete combustion of methanoic acid vapour according to the equation below?
2HCOOH(g)+O2(g)→2CO2(g)+2H2O(g) 2\text{HCOOH(g)} + \text{O}_2\text{(g)} \rightarrow 2\text{CO}_2\text{(g)} + 2\text{H}_2\text{O(g)} 2HCOOH(g)+O2(g)→2CO2(g)+2H2O(g)+498+498+498
−498-498−498
−996-996−996
+2040+2040+2040
