Gibbs Free Energy Calculations

Which statement is true regarding the desublimation of gaseous CO₂?

• ΔH is negative, ΔS is positive, and ΔG is negative at all temperatures.

• ΔH is positive, ΔS is negative, and ΔG is positive at all temperatures.

• ΔH is positive, ΔS is positive, and ΔG is positive at low temperature and negative at high temperature.

• ΔH is negative, ΔS is negative, and ΔG is negative at low temperature and positive at high temperature.

What is the significance of the change in Gibbs free energy (ΔG) for a reaction?

The change in Gibbs free energy for a process is ​ (a)   to the ​​ (b)   of ΔS_univ. Since ΔS_univ is a criterion for ​ (c)   , ΔG is also a criterion for ​ (d)   (although opposite in sign).

• proportional
• negative
• spontaneity
• inversely proportional
• slow reactions
• fast reactions
• positive
• high reaction yield

Calculate the change in Gibbs free energy for each set of ΔH°rxn, ΔS°rxn, and T. (Assume that all reactants and products are in their standard states.)

ΔH°rxn = +119 kJ ; ΔS°rxn = −242 J/K ; T = 308K

Express your answer in kilojoules to three significant figures.

ΔG°rxn = ___ KJ

Calculate the change in Gibbs free energy for each set of ΔH°rxn, ΔS°rxn, and T. (Assume that all reactants and products are in their standard states.)

ΔH°rxn = −119 kJ ; ΔS°rxn = +242 J/K ; T = 308 K
Express your answer in kilojoules to three significant figures.

ΔG°rxn = ___ kJ

Calculate the change in Gibbs free energy for each set of ΔH°rxn, ΔS°rxn, and T. (Assume that all reactants and products are in their standard states.)

ΔH°rxn = −119 kJ ; ΔS°rxn = −242 J/K ; T = 308 K

Express your answer in kilojoules to three significant figures.

ΔG°rxn = ___ kJ

Calculate the change in Gibbs free energy for each set of ΔH°rxn, ΔS°rxn, and T. (Assume that all reactants and products are in their standard states.)

ΔH°rxn = −119 kJ ; ΔS°rxn = −242 J/K ; T = 711 K

Express your answer in kilojoules to three significant figures.

ΔG°rxn = ___ kJ

Predict whether each reaction is spontaneous at the temperature indicated.

Drag the appropriate items to their respective bins.

Groups:

(a) Spontaneous

,

(b) Nonspontaneous

• Reaction in part C ΔG = -44.5 kJ

• Reaction In part B ΔG = -194 kJ

• Reaction in part D ΔG = 53.1 kJ

• Reaction in part A ΔG = 194 kJ