Answer:
C. ΔG is positive at low temperatures, but negative at high temperatures (and zero at some temperature).
Explanation:
Since we need to give energy in the form of heat to vaporize a liquid, the enthalpy is positive. In a gas, molecules are more separated than in a liquid, therefore the entropy is positive as well.
Considering the Gibbs free energy equation:
ΔG= ΔH - TΔS
+ +
When both the enthalpy and entropy are positive, the reaction proceeds spontaneously (ΔG is negative) at high temperatures. At low temperatures, the reaction is spontaneous in the reverse direction (ΔG is positive).
Is it multiple choice or do you just answer
(a)The change in Gibbs free energy for the reaction has been 2.6 kJ/mol.
(b) The change in Gibbs free energy for the reaction has been -49.3 kJ/mol.
(c) The change in Gibbs free energy for the reaction has been 91.38 kJ/mol.
1) concentration or partial pressure of species
involved. 2) temperature • 3) presence of catalyst
4) nature of reactants.
