Question 1
Paper 2Easy4 marksEthanol, C₂H₅OH(l), is used as a fuel. Its complete combustion produces carbon dioxide and liquid water. The standard enthalpies of formation at 298 K are:
| Substance | ΔH°f / kJ mol⁻¹ |
|---|---|
| C₂H₅OH(l) | −277.7 |
| O₂(g) | 0 |
| CO₂(g) | −393.5 |
| H₂O(l) | −285.8 |
(a)[2]
Write the balanced equation for the complete combustion of ethanol, including state symbols.
(b)[2]
Using the equation in (a) and the equation for enthalpies of formation in the data booklet, determine the standard enthalpy change for the combustion of 1 mol of ethanol. Give your answer in kJ mol⁻¹.