Which of the following reactions will have the greatest decreagf-b. y3ibjsf/ vw09p0u hr5sxe )mf1se in entropy?

  Which of the following combinations of ΔH ioovm0 9dy / wu;c,+gband ΔS results in the most spontaneous reaction at 2990wmgbd,iucov+ /o; y8 K?

  Which of the following statements about enth6ke.0dd- c zn5m9akwropy is incorrect?

  Which of the following compounds are akx t0)w6*c9g j7hdg.sueh ue :rranged 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 endothp 1:xqj vd-)jx.d,t j b1hhj*zermic reaction that results in an increase in entrodp*)1xtjjh-bjd,1 qx : hz. jvpy?

  Which statement about the relationshi :sbxt 9iw/1t,ya fu7np between Gibbs free energy change and the equilibu,:7xb9iywatsn/ 1tfrium constant is correct?

  Which of the following factors affec;tao 159(bakbg5nc1r-jn* cge rk )wht the entropy of a system containing gases? - b)n rn1bwhgkct ega5o;1j5a(kc9 *r
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 spontok /5w xhq1y2sl;vmnh ,8z6e oaneity of a reactiovlxz8n ,/m5w yhe26o ;q skho1n.
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 carboeop * m/ lx/15oc-cwgt0n(bfb n monoxide and hydrogen according to the following rea1n mbbf0(g /5*oxc/wocelp-tction:
$CO(g)$+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 tda nbsd9((;ug4jk g i5 a)y,jphe fermentation 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 toua3 d x 7jamsw22vn:,c chemical equilibrium?

  Consider the followinqw(pkeal*m8h rwgp8 ej43z 4- g reaction:
$C_2H_4$(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 ex +4*skpa n1aystent of reaction for a reversible y*a4n k+s1a spreaction.
At what point is the reaction at equilibrium?