Ethanol is used as a fuel additive. Its combustion at 298 K can be represented by the balanced equation:
C₂H₅OH(l) + 3 O₂(g) → 2 CO₂(g) + 3 H₂O(l)
A partial data table of standard molar entropies is provided.
Species S° (J·mol⁻¹·K⁻¹)
C₂H₅OH(l) 160.7
O₂(g) 205.0
CO₂(g) 213.7
H₂O(l) 69.9
(1) Determine the standard entropy change ΔS° for the combustion of one mole of ethanol at 298 K. Give your answer in J·mol⁻¹·K⁻¹ to four significant figures.
(2) Calculate the entropy change, in J·g⁻¹·K⁻¹, associated with the complete combustion of ethanol if the molar mass of ethanol is 46.07 g·mol⁻¹.