Gibb’s free energy is a thermodynamic quantity which gives the maximum reversible work at constant temperature and pressure.
It is also explained mathematically as,
Where, is the change in energy and is the change in entropy.
When the sign of is negative then the reaction is spontaneous and when the sign is positive then the reaction is non-spontaneous.
In the given question, you need to determine the value of for different reactions and then check the spontaneity of the reaction.
The change in energy during phase change or during a reaction is known as Enthalpy. When energy is absorbed during reaction or phase change the sign for enthalpy is taken as positive and when energy is released during reaction or phase change the sign for enthalpy is taken as negative.
The change in entropy (degree of randomness, ) during phase change or during a reaction is known as Entropy. When the degree of randomness is increased, it is given a positive sign and when degree of randomness is decreased, it is given a negative sign.
a
The reaction is
The Gibb’s free energy at 298 K for the above reaction is as follows:
b
The reaction is
The Gibb’s free energy at 298 K for the above reaction is as follows:
The temperature at which Gibb’s free energy is negative for the above reaction is calculated as follows:
Ans: Part a
The Gibb’s free energy for the reaction is negative, therefore, the reaction is spontaneous.
For the values give for ΔH and ΔS, calculate ΔG foreach for each of the following reactions at 298 K. If the reactionis...
A) 2PbS(s)+3O2(g)→2PbO(s)+2SO2(g), ΔH∘=−844 kJ, ΔS∘=−165 J/K Express the Gibbs free energy in kilojoules to three significant digits. B) 2POCl3(g)→2PCl3(g)+O2(g), ΔH∘=572 kJ, ΔS∘=179 J/K Express the Gibbs free energy in kilojoules to three significant digits. C) At what temperature (if any) would the decomposition of POCl3 become spontaneous? Express the temperature in kelvins to three significant digits. If there is no answer, enter none.
Use the data in Appendix B in the textbook to calculate ΔH∘ and ΔS∘ for each of the following reactions. From the values of ΔH∘ and ΔS∘, calculate ΔG∘ at 25 ∘C and predict whether each reaction is spontaneous under standard-state conditions. Part A 2SO2(g)+O2(g)→2SO3(g) Express your answer using four significant figures. ΔH∘ = kJ Part B Express your answer using four significant figures. ΔS∘ = J/K Part C Express your answer using four significant figures. ΔG∘ = kJ Part...
For a certain chemical reaction, ΔH∘=−39.0kJ and ΔS∘=−84.0J/K Calculate ΔG∘ for the reaction at 298 K. Is the reaction spontaneous at 298 K under standard conditions?
kindly help with 20 and 21 please 20. The sublimation of solid carbon dioxide is a spontaneous process. Predict the sign (+,-, or 0) of AG", AH", and AS, respectively. 21. Calculate AG for the following reaction at 298 K. 2PbS(s) + 3O2(g) → 2PbO(s) + 25O2(g) AH°= -844 kJ ASO= -165 J/K If the reaction is not spontaneous under standard conditions at 298K, at what temperature (if any) would the reaction become spontaneous?
Determine ΔG◦rxn using the following information. 2H2S(g)+3O2(g) ---> 2H2O(l)+2SO2(g) ΔH= +1.12kJ ;ΔS= -390.7J/K
A certain reaction has ΔH°= -19.5 kJ/mol and ΔS°= +42.7 J/mol K a) Is the reaction exothermic or endothermic? b) Does the reaction lead to an increase or decrease in the disorder of the system? c) Calculate ΔG° for the reaction at 298K. d) Is the reaction spontaneous at 298 K under standard conditions?
Calculate ΔG° for a reaction that has a ΔS° of 142.6 J/K and a ΔH° of 95.7 kJ occurring at standard conditions.
1a. ) Complete the table with signs and general values for K (ie: K<1 or K>1) Always spontaneous Always nonspontaneous Spontaneous at high temperatures ΔG ΔH ΔS K 2. Calculate the boiling point (in K) for the following: X2 (l) --) X2 (g) ΔH = +35 kJ ΔS = + 215 J/K (HINT: what does ΔG equal when a reaction switches from spontaneous to nonspontaneous?) 1b. ) Trick question (refer to the table in #1): at what temperature does the...
For the reaction: C(s) + H2O(g) CO(g) + H2(g), ΔH° = 131 kJ and ΔS° = 128 J/K at 298 K. At temperatures greater than ______ K, this reaction is spontaneous under standard conditions. a. 1.02 K b. 273 K c. 1023 K d. 753 K
For the following reaction: 2 CO(g) + O2(g) → 2 CO2(g), given ΔH = -566 kJ and ΔG = -514 kJ, find ΔS (J/K) at 25 oC. Multiple Choices: ΔS = -174 J/K ΔS = -0.174 J/K ΔS = -2.08J/K ΔS = 174 J/K ΔS = -2080 J/K