Which of the following zj h 0uu8rl-*mb:/efi reactions will have the greatest decrease in entropy?

  Which of the following combiffw4*8k kpg 0izze-beahk 84 (nations of ΔH and ΔS results in the most spontaneous reaction atg4*wp f zekkhz0fi-eka4 (8b 8 298 K?

  Which of the following statements anpm o:+fvl4tz 3b u:l*bout entropy is incorrect?

  Which of the following compounds are arra6)3hqalke2 t rs4 b4-b xvg)wynged 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 increaseb(z9 krmr6 9pnxx8gv tld1*9x in ert9z*b9 vk (nxr96 xdl81pg mxntropy?

  Which statement about the relationship between Gibbs free energy chan.gy s5qs(b*o/tujc8o hl08(el7 u pzz ge and the equilibrium constant .z8(y*s zu0bt5soeup/l 7 lqh( c8jgois correct?

  Which of the following factors affect the entropy of a system containz1bp6 v k t1fdn dy-,wqvdlv2t/6t9n/ing gases? byzl/d k 2v1vw pd6dnv9f-1, nqt6/tt
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 the spow z2 ri 66w/jyhkuw4gfj /90xuntaneity of a reactiw9jwgzi 4y u 0/6x2 hu/j6wfkron.
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 carbon monoxide and hydrogen according to the flby dy 2(hx77y;i/mnr ollowing rxdyrhl;ybm i7/ (7ny2eaction:
$CO(g)$+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 fermentati/e,t hdsjxw1 +on of glucose:
$C_6H_12O_6$(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 chemiac1wg,1 3psbi6+anx4 z- q zsncal equilibrium?

  Consider the following rekahbl3ro/*dx0ky/ ya (2 yif;action:
$C_2H_4$(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 thehqwj2z .wp x0)xm5m,k extent of reaction f0h2 qj,kmwxm5zx.pw )or a reversible reaction.
At what point is the reaction at equilibrium?