Final answer:
The standard enthalpy of formation of liquid ethanol is represented by the thermochemical equation involving the synthesis of one mole of ethanol from carbon (solid), hydrogen (gas), and oxygen (gas) with an enthalpy change of -277.6 kJ/mol.
Step-by-step explanation:
The equation that represents the standard enthalpy of formation of liquid ethanol (C2H5OH) is as follows:
C(s) + 3 H2(g) + ½ O2(g) → C2H5OH(l) ∆H° = -277.6 kJ/mol
This equation shows the formation of one mole of liquid ethanol from its elements in their standard states, which are solid carbon, gaseous hydrogen, and diatomic oxygen gas. The standard enthalpy of formation of a pure substance is the heat change that occurs when one mole of a substance is formed from its constituent elements in their standard states at standard conditions (25°C and 1 atmosphere pressure).