Question 1

The hydrolysis of ATP to ADP is spontaneous.However,the reaction of glucose with monohydrogen phosphate,the first step in the oxidation of glucose,is not spontaneous.Determine whether the coupled reactions are spontaneous.

Accepted Answer

The coupling of a non-spontaneous reaction (like the phosphorylation of glucose) with a spontaneous one (like the hydrolysis of ATP to ADP) can make the overall process spontaneous if the net free energy change (ΔG) for the combined reactions is negative.

Question 2

Which of the following would have the largest calculated value of the residual entropy?

Accepted Answer

The larger the number of possible arrangements of molecules, the larger the residual entropy. Chlorobenzene (A) has a larger number of possible arrangements compared to the other compounds due to its complex structure.

Question 3

The standard reaction free energy for the oxidation of glucose is -2879 kJ·mol^-1.What is the maximum nonexpansion work obtainable from 125 g glucose,C₆H₁₂O₆(s)?

Accepted Answer

The answer of The standard reaction free energy for the...

Question 4

The energy levels of two particle in a box systems are given below: Which molecule,N₂,or F₂,is better represented by (b)?

Accepted Answer

The answer of The energy levels of two particle in...

Question 5

When barium hydroxide is dissolved in water,the temperature of the solution increases.Which of the following statements regarding this reaction is true?

Accepted Answer

The dissolution of barium hydroxide in water is an exothermic process, as indicated by the increase in temperature. This suggests that the reaction releases energy, making it favorable or spontaneous. The spontaneity of a reaction at all temperatures doesn't solely depend on entropy or enthalpy changes but on the overall free energy change. However, the statement that it is spontaneous at all temperatures might be an oversimplification for educational purposes, as it emphasizes the exothermic nature of the reaction, which generally increases the spontaneity of the process.

Question 6

Draw a graph of the molar Gibbs free energy versus temperature for H₂O(l)and H₂O(g). (a)Explain the slopes of the 2 lines. (b)At low temperatures,which phase is most stable? (c)At high temperatures,which phase is more stable?

Accepted Answer

The answer of Draw a graph of the molar Gibbs...

Question 7

Iodine sublimes at room temperature.The reaction free energy,enthalpy,and entropy for this reaction,respectively,are

Accepted Answer

Sublimation is an endothermic process, so the enthalpy change is positive. The entropy increases as solid iodine becomes gas, so the entropy change is positive. The free energy change is negative for a spontaneous process like sublimation at room temperature.

Question 8

Reactions with positive values of $\Delta$S_r^o always become spontaneous at low temperatures.

Accepted Answer

Reactions with positive values of ∆G will not be spontaneous at low temperatures. A reaction becomes spontaneous only when ∆G is negative.

Question 9

Water slowly evaporates at 25^oC.Which of the following statements regarding this reaction is true?

Accepted Answer

The evaporation of water at room temperature (25°C) is a spontaneous reaction because water at room temperature is in its liquid phase and has high entropy (disorder). When water evaporates, it becomes a gas which has an even higher degree of entropy. Therefore, this reaction is entropy-driven. The sign of the reaction enthalpy is positive (+) because energy is required to break the intermolecular bonds between water molecules. The sign of the reaction entropy is also positive (+) because the degree of disorder increases when water evaporates.

Question 10

The reaction CaO(s)+ H₂O(l)→ Ca(OH)₂(s) Is spontaneous at 0^oC.Pedict the sign of the reaction enthalpy and entropy,respectively.

Accepted Answer

The answer of The reaction CaO(s)+ H₂O(l)→ Ca(OH)₂(s) Is spontaneous at...

Question 11

The dehydrogenation of cyclohexane,C₆H₁₂(l),to form benzene,C₆H₆(l),is not spontaneous.However,the hydrogenation of ethene to form ethane is spontaneous.Calculate the reaction free energy for the coupled reaction C₆H₁₂(l)+ 3CH₂=CH₂(g)$\rightarrow$ C₆H₆(l)+ CH₃CH₃(g)

Accepted Answer

The answer of The dehydrogenation of cyclohexane,C₆H₁₂(l),to form benzene,C₆H₆(l),is not...

Question 12

Predict the sign of the molar Gibbs free energy for the process H₂O(s)→ H₂O(l)at 1 atm and 1^oC,0^oC,and -1^oC,respectively.

Accepted Answer

At 1°C, ice melts spontaneously, so ΔG is negative. At 0°C, the system is at equilibrium, so ΔG is zero. At -1°C, ice does not melt spontaneously, so ΔG is positive.

Question 13

All the halogens exist as diatomic molecules at room temperature and 1 bar.Under these conditions,which of the halogens,F to I,has the smallest molar entropy?

Accepted Answer

The answer of All the halogens exist as diatomic molecules...

Question 14

The energy levels of two particle in a box systems are  Which system has the higher entropy?

Accepted Answer

The answer of The energy levels of two particle in...

Question 15

Predict the sign (+,-,0)of the entropy change when a glass of water reversibly loses 200 J of energy at 25°C.

Accepted Answer

The answer of Predict the sign (+,-,0)of the entropy change...

Quiz 9: Thermodynamics: The Second and Third Laws

The hydrolysis of ATP to ADP is spontaneous.However,the reaction of glucose with monohydrogen phosphate,the first step in the oxidation of glucose,is not spontaneous.Determine whether the coupled reactions are spontaneous.

Which of the following would have the largest calculated value of the residual entropy?

The standard reaction free energy for the oxidation of glucose is -2879 kJ·mol^-1.What is the maximum nonexpansion work obtainable from 125 g glucose,C₆H₁₂O₆(s)?

The energy levels of two particle in a box systems are given below: Which molecule,N₂,or F₂,is better represented by (b)?

When barium hydroxide is dissolved in water,the temperature of the solution increases.Which of the following statements regarding this reaction is true?

Draw a graph of the molar Gibbs free energy versus temperature for H₂O(l)and H₂O(g). (a)Explain the slopes of the 2 lines. (b)At low temperatures,which phase is most stable? (c)At high temperatures,which phase is more stable?

Iodine sublimes at room temperature.The reaction free energy,enthalpy,and entropy for this reaction,respectively,are

Reactions with positive values of $\Delta$ S_r^o always become spontaneous at low temperatures.

Water slowly evaporates at 25^oC.Which of the following statements regarding this reaction is true?

The reaction CaO(s) + H₂O(l) → Ca(OH) ₂(s) Is spontaneous at 0^oC.Pedict the sign of the reaction enthalpy and entropy,respectively.

The dehydrogenation of cyclohexane,C₆H₁₂(l),to form benzene,C₆H₆(l),is not spontaneous.However,the hydrogenation of ethene to form ethane is spontaneous.Calculate the reaction free energy for the coupled reaction C₆H₁₂(l)+ 3CH₂=CH₂(g) $\rightarrow$ C₆H₆(l)+ CH₃CH₃(g)

Predict the sign of the molar Gibbs free energy for the process H₂O(s) → H₂O(l) at 1 atm and 1^oC,0^oC,and -1^oC,respectively.

All the halogens exist as diatomic molecules at room temperature and 1 bar.Under these conditions,which of the halogens,F to I,has the smallest molar entropy?

The energy levels of two particle in a box systems are Which system has the higher entropy?

Predict the sign (+,-,0)of the entropy change when a glass of water reversibly loses 200 J of energy at 25°C.

Quiz 9: Thermodynamics: The Second and Third Laws

The hydrolysis of ATP to ADP is spontaneous.However,the reaction of glucose with monohydrogen phosphate,the first step in the oxidation of glucose,is not spontaneous.Determine whether the coupled reactions are spontaneous.

Which of the following would have the largest calculated value of the residual entropy?

The standard reaction free energy for the oxidation of glucose is -2879 kJ·mol-1.What is the maximum nonexpansion work obtainable from 125 g glucose,C6H12O6(s)?

The energy levels of two particle in a box systems are given below: Which molecule,N2,or F2,is better represented by (b)?

When barium hydroxide is dissolved in water,the temperature of the solution increases.Which of the following statements regarding this reaction is true?

Draw a graph of the molar Gibbs free energy versus temperature for H2O(l)and H2O(g). (a)Explain the slopes of the 2 lines. (b)At low temperatures,which phase is most stable? (c)At high temperatures,which phase is more stable?

Iodine sublimes at room temperature.The reaction free energy,enthalpy,and entropy for this reaction,respectively,are

Reactions with positive values of Δ\DeltaΔ Sro always become spontaneous at low temperatures.

Water slowly evaporates at 25oC.Which of the following statements regarding this reaction is true?

The reaction CaO(s) + H2O(l) → Ca(OH) 2(s) Is spontaneous at 0oC.Pedict the sign of the reaction enthalpy and entropy,respectively.

The dehydrogenation of cyclohexane,C6H12(l),to form benzene,C6H6(l),is not spontaneous.However,the hydrogenation of ethene to form ethane is spontaneous.Calculate the reaction free energy for the coupled reaction C6H12(l)+ 3CH2=CH2(g) →\rightarrow→ C6H6(l)+ CH3CH3(g)

Predict the sign of the molar Gibbs free energy for the process H2O(s) → H2O(l) at 1 atm and 1oC,0oC,and -1oC,respectively.

All the halogens exist as diatomic molecules at room temperature and 1 bar.Under these conditions,which of the halogens,F to I,has the smallest molar entropy?

The energy levels of two particle in a box systems are Which system has the higher entropy?

Predict the sign (+,-,0)of the entropy change when a glass of water reversibly loses 200 J of energy at 25°C.

The standard reaction free energy for the oxidation of glucose is -2879 kJ·mol^-1.What is the maximum nonexpansion work obtainable from 125 g glucose,C₆H₁₂O₆(s)?

The energy levels of two particle in a box systems are given below: Which molecule,N₂,or F₂,is better represented by (b)?

Draw a graph of the molar Gibbs free energy versus temperature for H₂O(l)and H₂O(g). (a)Explain the slopes of the 2 lines. (b)At low temperatures,which phase is most stable? (c)At high temperatures,which phase is more stable?

Reactions with positive values of $\Delta$ S_r^o always become spontaneous at low temperatures.

Water slowly evaporates at 25^oC.Which of the following statements regarding this reaction is true?

The reaction CaO(s) + H₂O(l) → Ca(OH) ₂(s) Is spontaneous at 0^oC.Pedict the sign of the reaction enthalpy and entropy,respectively.

The dehydrogenation of cyclohexane,C₆H₁₂(l),to form benzene,C₆H₆(l),is not spontaneous.However,the hydrogenation of ethene to form ethane is spontaneous.Calculate the reaction free energy for the coupled reaction C₆H₁₂(l)+ 3CH₂=CH₂(g) $\rightarrow$ C₆H₆(l)+ CH₃CH₃(g)

Predict the sign of the molar Gibbs free energy for the process H₂O(s) → H₂O(l) at 1 atm and 1^oC,0^oC,and -1^oC,respectively.