At 298 K the combustion of liquid benzene is described by
C₆H₆(l) + 7.5 O₂(g) → 6 CO₂(g) + 3 H₂O(l) ΔS° = +250 J·mol⁻¹·K⁻¹.
Determine ΔS° (in kJ·mol⁻¹·K⁻¹) for the reaction written below, in which all stoichiometric coefficients have been divided by three and the direction has been reversed.
2 CO₂(g) + H₂O(l) → ⅓ C₆H₆(l) + 2.5 O₂(g)
a) +0.083kJmol−1K−1
b) −0.250kJmol−1K−1
c) −0.083kJmol−1K−1
d) −0.833kJmol−1K−1