Multiple Choice
What are the signs of ∆H, ∆S and ∆G for the spontaneous conversion of a solid into gas?
7. Energy, Rate and Equilibrium
Gibbs Free Energy (Simplified)
Back7. Energy, Rate and Equilibrium
Gibbs Free Energy (Simplified)
- Multiple Choice
Consider the combustion of butane gas and predict the signs of ΔS, ΔH and ∆G.
C4H10(g) + 13/2 O2(g) ⟶ 4 CO2(g) + 5 H2O(g)
- Multiple Choice
A particular reaction has ΔG = –350 kJ and ΔS = –350 J/K at 24°C. How much heat will be released/absorbed?
- Multiple Choice
For a reaction in which ΔH = 125 kJ and ΔS = 325 J/K, determine the temperature in Celsius above which the reaction is spontaneous.
- Open QuestionThe change of state from liquid H2O to gaseous H2O has ∆H = +9.72 kcal/mol(+40.7 kJ/mol) and ∆S = -26.1 cal/(mol • K) [-109 J/(mol •K)].Is the change from liquid to gaseous H2O favored or unfavored by ∆H? By ∆S?
- Open QuestionThe change of state from liquid H2O to gaseous H2O has ∆H = +9.72 kcal/mol(+40.7 kJ/mol) and ∆S = -26.1 cal/(mol • K) [-109 J/(mol •K)].What are the values of ∆H and ∆S (in kcal/mol and kJ/mol) for the change from gaseous to liquid H2O?
- Open QuestionTwo curves are shown in the following energy diagram:
Which curve represents the spontaneous reaction, and which the nonspontaneous? - Open QuestionThe following diagram portrays a reaction of the type A(s) → B(g) + C(g), where the different-colored spheres represent different molecular structures. Assume that the reaction has ∆H = +9.1 kcal/mol (+38.1 kJ/mol). Is the reaction likely to be spontaneous at all temperatures, nonspontaneous at all temperatures, or spontaneous at some but nonspontaneous at others?
- Open QuestionThe following diagram portrays a reaction of the type A(s) → B(g) + C(g), where the different-colored spheres represent different molecular structures. Assume that the reaction has ∆H = +9.1 kcal/mol (+38.1 kJ/mol). What is the sign of ∆S for the reaction?
- Open QuestionWhat two factors affect the spontaneity of a reaction?
- Open QuestionWhat is the difference between an exothermic reaction and an exergonic reaction?
- Open QuestionUnder what conditions might a reaction be endothermic but exergonic? Explain.
- Open QuestionFor the reaction 2 Hg(l) O2 → 2HgO(s), ∆H = -43 kcal/mol (-180 kJ/mol).Under what conditions would you expect this process to be spontaneous?
- Open QuestionThe reaction between hydrogen gas and carbon to produce the gas known as ethylene is:2 H2(g) + 2 C(s) → H2C=CH2(g), ∆G = +16.3 kcal/mol (+68 kJ/mol) 25 °C.Is this reaction spontaneous at 25 °C?