Which of the following reactions will have the greatest decrease 0iio(7 vpcy9uh + w (f4raawl9hgq s9+in entropy?

  Which of the following combinati:i9ogm tez00m ons of ΔH and ΔS results in the most spontaneous reaction at m9zi0t m0geo: 298 K?

  Which of the following statements about entrod,* gtfu3t gj;nuh c/.py is incorrect?

  Which of the following compounds are gljt /r-5 cc0qxexk0 1arranged 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 reav:zb b2)8yswj.gogn h/a br6)ction that results in an increase in evgr2j8s:6)o g w)h b.zna/ybbntropy?

  Which statement about the relationship between Gibbs free kbssu cw*+ / ld+7sx/uk.26,vcl4 a b*anzenzenergy change and the equilibrium constant is /u *z+lknb sakas* ,swz.c v4/6u cx2l7be+ndcorrect?

  Which of the following factors affect the entropy of a system containing gaslc-kgb gw5zu;w88v l due7hk90r:9x aes? a:zr kw bu8 u07gh8vcx9;5ge9dkw-ll
I. The temperature of the system
II. The states of the system
III. The pressure of the system

  The Gibbs free energy cha9tja5)e9 pel bv6j za+nge can be used to determine the spontaneity of a reactionvtp6 a9jjeb59)l +z ae.
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 o,n2kzmrx(f*)n l /fo and hydrogen according to the following reax(rff*)oo 2n ,kz /lnmction:
$CO(g)$+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 produceu /wnjczi-6w 9z -( )wwaz 6p7rft;kwrd through the 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 to chemic nokt:v1 qxf72al equilibrium?

  Consider the followingp vdpbu vmf. -8;0df55lx2vkw 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 Giy(dqb8fr:qxtbb) i pw ;:: ic5bbs free energy against the extent of reaction for a reversible reactii:xirw dbq qb; 8 5fc:()p:tybon.
At what point is the reaction at equilibrium?