Which of the following react ryv7-1 ;mnifrions will have the greatest decrease in entropy?

  Which of the following combinations of ΔH and p+q8n hitmqo32wx3z2z9uw b,ΔS results in the most spontaneous reacu p293z8nqq wz mi,ob2ht +w3xtion at 298 K?

  Which of the following statements aih- no18ozqh.bout entropy is incorrect?

  Which of the following compounds are arranged in order of decy4ubf1kpzy 62 reasing entropy?

$C$(s)
$H_2O$(l)
$O_2$
$CO_2$(g)
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  Which statement is true for an endothermi9tzs.c/: vwk t, (clkic reaction that results in an increase in entropy?(lz 9cvsc tiw/ k,.tk:

  Which statement about the relationship between Gibbs frfv3*f3 v0 kw j bbpd,h*ua8nip3 h*o0cee energy change and the equilibrium constant is corrb jkoi,u dhfpf*n300 8p*vabwc33v h*ect?

  Which of the following factors affect the entropy of am1rm 79 s7/*nv;3qtyakbotno4 l4p qq system containing gases? s7/ 1oya3mt;4vrqq *k4mtol97b n nqp
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 useof(i ipf4+etgp vqz0rbs(; 054 fq- ywd to determine the spontaneity of a reaction. o(yzi4q i 4rf(qtv ; -w5fpge0s 0p+fb
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 reac87.jtel4arrur2/vyy mbpm2)/5 csyyting carbon monoxide and hydrogen according to the following ra)y/trm.rb2up yc8yj54vl7ye m2 /s r eaction:
$CO(g)$+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 gl/lx+k7dqjh7 uo3q z oe1k*366gar iuhucose:
$C_6H_12O_6$(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 chemical equx tl ,s9.bcy1xf*pctt,y w1 f;ilibrium?

  Consider the following reacgzx3w4c m (zx6akf3k5eep3 k6tion:
$C_2H_4$(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 extenk l *l266n9t bfp2awry4jho,v t of reaction fj 2,h wptl*6bl4yan ro6 f92kvor a reversible reaction.
At what point is the reaction at equilibrium?