Which of the following reactions will have the greatest decrease in entropv byvwd*a3)q+y?

  Which of the following combinations of ΔH a1ebe)x7f+m; ,yra)uteex kg.nd ΔS results in the most spontaneous reaction at 29mx;e rx 1et,+ )eukg7bf.yae)8 K?

  Which of the following statements about entropyf9*xpp4b1vvy*pb l c ag:9ty * is incorrect?

  Which of the following compounds are arrangedke nule,xep- gcy) 70c-tp :*a in order of decreasing entropy?

$C$(s)
$H_2O$(l)
$O_2$
$CO_2$(g)
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  Which statement is true for an endothermic reaction that results in an incre5 ejbl7e.r(z.erica91fw7 i tase ine1ia z (ei.e75b 9r7r tcjlwf. entropy?

  Which statement about the relationsp.0h fic8xum z o 2i-*qsn4gk*2)kt fghip between Gibbs free energy change and the equilibrium constant is cis20ufxok4mg2 -.z ) qp nt*kgi8c* fhorrect?

  Which of the following factors affect the ent :shf,cjq m3bz3 xsz (-ur8w1gropy of a system containing gases? r3-x: zcwubzmh81sj( gq ,f3s
I. The temperature of the system
II. The states of the system
III. The pressure of the system

  The Gibbs free energy change can be used to determine t ij c/gs (cyq628ou3/f1ksgzc he spontaneity of a reactionjc( /os 6gz 3cs/8ycgk u2qf1i.
1.1.Define Gibbs free energy change of formation.
1.2.Define spontaneous reaction.

2.1.State a correctly balanced equation that represents the complete combustion of butane.

2.2.Using section 12 (Section 13- 2025 Syllabus) of the data booklet, calculate the Gibbs free energy change of this reaction.
ΔG$_{reaction}$=-  kJ mol$^{-1}$
2.3.State, with a reason, whether this reaction is spontaneous or not.

Important note: The section numbers mentioned in the video solution are specific to the 2024 syllabus.
You can refer to the question stem to find the section numbers in the 2025 syllabus.

  Methanol is produced by reacting carbonv b6lyu2 5j/xy monoxide and hydrogen according to the followinx5yj/uvb y62l g reaction:
$CO(g)$+2$H_2(g)$ → $CH_3OH$(g)
$CO(g)$+2$H_2(g)$ ← $CH_3OH$(g)
1.Deduce the equilibrium constant expression for the formation of methanol.
At 500$^{\circ}C$ ,a 750cm$^3$ sealed flask is found to contain 0.923 mol of CH_3OH, 0.352mol of CO and 0.124 mol of $H_2$.
2.1.Calculate the value of K$_c$ at 500 $^{\circ}C$. K$_c$=  
2.2.Using sections 1 and 2 of the data booklet, calculate ΔG$^θ$ at 500 $^{\circ}C$.
T=  K;ΔG$^θ$=-  kJ mol$^{-1}$

  Ethanol can be produced through the fermentation of glucm1. ,jv /tboyn mtr67 bd0.gyxose:
$C_6H_12O_6$(aq)→2$C_2H_5OH$(l)+2$CO_2$(g)
1.1.Predict whether the entropy change for this reaction is positive or negative. Explain your reasoning.
1.2.The absolute entropy for glucose is +209.2 J K$^{-1}$ mol$^{-1}$.Using section 12 (Section 13- 2025 Syllabus) of the data booklet, calculate the entropy change for this reaction.
ΔS$_{reaction}$=+  JK$^{-1}$ mol$^{-1}$

2.The enthalpy of formation of glucose is -1273.3kJ mol$^{-1}$.Using section 12 (Section 13- 2025 Syllabus) of the data booklet, calculate the enthalpy change for this reaction.
ΔH$_{reaction}$=-  kJ mol$^{-1}$

3.Using your answers to (a)(ii) and (b), calculate the Gibbs free energy change at 298K.
ΔG=-  kJ mol$^{-1}$
Important note: The section numbers mentioned in the video solution are specific to the 2024 syllabus.
You can refer to the question stem to find the section numbers in the 2025 syllabus.

  Dry ice, solid $CO_2$,is commonly used as a cooling or freezing agent in the medical and food industries.
1.Write an equation representing the sublimation of $CO_2$.
2.The enthalpy of sublimation for $CO_2$ is +26.1kJ mol$^{-1}$ and the absolute entropy of $CO_2$ in the solid state is 51.1 J K$^{-1}$ mol$^{-1}$.
2.1.Using section 12 (Section 13- 2025 Syllabus) of the data booklet, calculate the entropy change associated with the sublimation of $CO_2$.
ΔS$_{reaction}$=+  J K$^{-1}$ mol$^{-1}$
2.2.Using your answer to (bi), calculate the Gibbs free energy change for the sublimation of $CO_2$ at K.
ΔG=-  kJ mol$^{-1}$

3.Calculate the minimum temperature at which $CO_2$ sublimates.
T＞  K

Important note: The section numbers mentioned in the video solution are specific to the 2024 syllabus.
You can refer to the question stem to find the section numbers in the 2025 syllabus.

  How does Gibbs free energy relate to chemica .m*)hde -u:tv a9ym8cegdw,gl equilibrium?

  Consider the following reactionw3j* fi k7fz0t:
$C_2H_4$(g)+$H_2$(g)→$C_2H_6$(g)
ΔH is -136kJ mol$^{-1}$
ΔS is -121jk$^{-1}$ mol$^{-1}$
ΔG at 298K is -99.9kJ mol$^{-1}$
1.1.Explain why the enthalpy of formation of $H_2$ is 0 kJ mol$^{-1}$.
1.2.Explain why the entropy change for this reaction is negative.

2.Explain how a reaction can be spontaneous with a negative entropy change.

3.Calculate the temperature at which this reaction is no longer spontaneous.
T=  K

  The following graph shows the Gibbs free energy against the extent of,qvz9p nc46q+ 0fved4ujmy* u reaction for a reversible reacp u+ q4e yc,vduf4qj9v0m6zn* tion.
At what point is the reaction at equilibrium?