Question

For a reaction at 25°C enthalpy change and entropy change are – 11.7×10³ J mol^–1 and $- 105Jmol^{- 1}K^{- 1}$ respectively, what is the Gibb's free energy.

• A. 15.05 kJ
• B. 19.59 kJ
• C. 2.55 kJ
• D. 22.55 kJ

Answer 1

Answer: (B)

19.59 kJ

Answer 2

$\Delta G = \Delta H - T\Delta S,$ $T = 25 + 273 = 298K$

$\Delta G = - 11.7 \times 10^{3} - 298 \times ( - 105)$ $= 19590J = 19.59kJ$