Which of the following reactions will have the greatest dery,rp b k9cg hf)r/3tiwa) g:)crease in entropy?

  Which of the following combinationsftf- xz+ od3tw utz/*: of ΔH and ΔS results in the most spontaneous react-u3tz xf:+ zt*ot/d fwion at 298 K?

  Which of the following st7vai0 v x7;-a0b6v/pkh mbqwu atements about entropy is incorrect?

  Which of the followin5o fk8)y5jqjzt5fma1g compounds are arranged 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 red w ld,w.ifo(x6ke- 1zaction that results in an increase in entropzfel do,xdk-w 1w. (i6y?

  Which statement about the relationshi1q3yzc8nahgb a; hj18p between Gibbs free energy change and the equilibrium constant is c8ghqnja 8a h1byz;1c3orrect?

  Which of the following factors affect the entropy of a system containing gases?6atjbh.h 7r*q3fwh ,b t 7,6f3rjhawh*qh. bb
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 determin /, fu7qnwbx c.kbake)p)3bh*,m8i b ve the spontaneity of a reaction,i pk*m ckbwbb,eh7nv)f )u/qb83.a x.
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 accordinze yyfx7 -/re0-sp a a,nl ja*qq5cu0)g to the following reaction:n--5ycaj0fleapyu rea*0 7)szq,q x /
$CO(g)$+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 throughg*g; 5r: v2//8wn t,winu7vv smdzxvz ) wbe8z 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 e 1.nwk: z g6shi 5xzqc((j6u4i crh3gvnergy relate to chemical equilibrium?

  Consider the following reactioy+6qjbu:llr 5gu5t: rn:
$C_2H_4$(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 remybrx8w t( eptcw2q340: uu 1g anyhk44z if07action for a reversible1x( 08ci3em z uqthwrufya0tnk42:ywg4 47b p reaction.
At what point is the reaction at equilibrium?