Calculate the standard entropy change for the reaction at 25 °C. Standard molar entropy values can be found in this table. C3H8(g)+5O2(g)⟶3CO2(g)+4H2O(g)

Answer 1

To calculate the standard entropy change (ΔS°) for the reaction, we need to use the standard molar entropies (S°) of the reactants and products.

The equation for the standard entropy change is:

ΔS° = ΣnS°(products) - ΣmS°(reactants)

where n and m are the stoichiometric coefficients of the products and reactants, respectively.

Using the values from the table provided, we have:

ΔS° = [3S°(CO2) + 4S°(H2O)] - [S°(C3H8) + 5S°(O2)]

ΔS° = [3(213.7 J/molK) + 4(188.8 J/molK)] - [269.9 J/molK + 5(205.0 J/molK)]

ΔS° = (641.1 J/molK + 755.2 J/molK) - (269.9 J/molK + 1025.0 J/molK)

ΔS° = 1169.6 J/molK - 1294.9 J/molK

ΔS° = -125.3 J/mol*K

Therefore, the standard entropy change for the reaction at 25°C is -125.3 J/mol*K.