Question 1

When a molecule of ethylenediamine replaces two molecules of NH₃ in Co(NH₃) , the entropy of the system ________

Accepted Answer

When a molecule of ethylenediamine replaces two molecules of NH₃ in Co(NH₃) 11eaa952_9b1c_58ee_ae90_01d80a3ba821_TB3835_11 , the entropy of the system increases. This is because ethylenediamine has a higher degree of disorder compared to NH₃, which means that the system has more possible microstates after the replacement, resulting in an increase in entropy.

Question 2

Consider a closed container containing a 1 M solution of HCl, above which is air that contains water vapor at its equilibrium vapor pressure. Assume the pressure of the air and water vapor is 1 bar and the temperature of the system is 298 K. Which of the following is/are in its their thermodynamic standard state?
I. the liquid water
II. the HCl solution
III. the water vapor

Accepted Answer

The answer of Consider a closed container containing a 1...

Question 3

Indicate which one of the following reactions most certainly results in a negative $\Delta$S_sys.

Accepted Answer

The answer of Indicate which one of the following reactions...

Question 4

Perfect crystals of carbon monoxide (CO) are difficult to prepare because the very small dipole moment allows a few molecules to align in a pattern such as CO OC CO instead of CO CO CO. If such disordered crystals were cooled to 0 K, what would be the value of their absolute entropy?

Accepted Answer

The absolute entropy of a disordered crystal at 0 K is greater than zero due to the residual entropy from the disorder.

Question 5

Before class, students were distributed throughout a classroom. When the bell rang, all the students sat down at three tables in the center of the room. The entropy of the class ________

Accepted Answer

The entropy of the class decreased because the students went from a state of being spread out (higher disorder) to a state of being concentrated at three tables (lower disorder). Entropy is a measure of disorder or randomness, and gathering in a smaller area represents a decrease in entropy.

Question 6

Indicate which one of the following reactions most certainly does not result in a decrease in entropy.

Accepted Answer

The answer of Indicate which one of the following reactions...

Question 7

Indicate which one of the following reactions results in a positive $\Delta$S_sys.

Accepted Answer

This reaction has a positive F1F1F1S1F1F1F10S_sys. The other reactions either have a negative or no change in this value.

Question 8

The enthalpy of vaporization for toluene (C₇H₈) is 380.00 kJ/kg, and its boiling point is 110.6S1U1P1$\circ$S1S1P0C. What is the entropy change when 0.75 mole of toluene vaporizes at 110.6S1U1P1$\circ$S1S1P0C?

Accepted Answer

From the given information:

Enthalpy of vaporization (ΔHvap) = 380.00 kJ/kg

Boiling point (Tb) = 110.6°C = 383.75 K

Number of moles of toluene vaporized (n) = 0.75 mol

To calculate the entropy change (ΔS) during the vaporization of toluene, we can use the following formula:

ΔS = ΔHvap / Tb * n

Substituting the given values, we get:

ΔS = 380.00 kJ/kg / 383.75 K * 0.75 mol

ΔS = 68.5 J/K

Therefore, the correct answer is (C).

Question 9

The following figures represent distributions of two types of gas molecules between two containers connected by an open tube. In which figure is the entropy of the system maximized?

Accepted Answer

The entropy of a system is directly proportional to the number of available microstates, or ways the system can be arranged while maintaining the same energy and number of particles. In figure C, the gas molecules are evenly distributed between the two containers, which means there are many ways the molecules can be arranged while maintaining the same distribution. This results in a higher number of available microstates and therefore a higher entropy compared to the other figures where the molecules are not evenly distributed.

Question 10

Indicate which one of the following reactions results in a negative $\Delta$S_sys.

Accepted Answer

The answer of Indicate which one of the following reactions...

Question 11

Which of the following will have the greatest standard molar entropy (SS1U1P1$\circ$S1S1P0)?

Accepted Answer

NH3(g) will have the greatest standard molar entropy because gases generally have higher entropy than liquids and solids due to the greater freedom of movement and higher number of microstates available to gas molecules. Among the options, NH3(g) is the only gas, and it has a relatively complex molecular structure, which contributes to its higher entropy compared to the simpler gas, solid, and liquid substances listed.

Question 12

At 0 K, the entropy of a perfect crystal is ________

Accepted Answer

At 0 K, the atoms in a crystal are in their lowest energy state and are ordered in a perfect lattice. This means that there is only one possible arrangement of atoms, resulting in zero positional disorder and a perfect crystal lattice structure. As entropy is a measure of the degree of disorder or randomness in a system, a perfect crystal at 0 K has zero entropy, which is denoted as S = 0. Therefore, the correct answer is B: (F1F1F1S1F1F1F10 0.)

Question 13

Which of the processes A-D will lead to a positive change in the entropy of the system?

Accepted Answer

The escape of helium gas from a balloon leads to a positive change in entropy because the gas particles disperse into a larger volume, increasing the disorder of the system.

Question 14

Which of the following processes will lead to a decrease in the entropy of the system?

Accepted Answer

The formation of rust involves the bonding of iron and oxygen atoms, resulting in a decrease in the number of free particles and thus a decrease in entropy. The other choices involve an increase in entropy - salt crystals dissolve to form more dispersed ions in solution, air escaping from a balloon results in a more dispersed gas, and ice melting in your hand increases the number of particles and their freedom of movement. Option E is also incorrect, as spontaneity does not necessarily mean a decrease in entropy.

Question 15

Before class, students were seated at three tables. When the school alarm went off suddenly, all the students distributed throughout the room to collect their belongings. The entropy of the class ________

Accepted Answer

The distribution of the students throughout the room is a more disordered state than when they were all seated at three tables, thus increasing the entropy of the class.

Question 16

Which of the following graphs best depicts the entropy of a pure substance as the temperature is raised from its solid form through its liquid and gaseous forms?

Accepted Answer

The answer of Which of the following graphs best depicts...

Question 17

The gas above the liquid in a sealed bottle of soda is primarily carbon dioxide. Carbon dioxide is also dissolved in the soda. When the distribution of carbon dioxide between the gas and liquid is at equilibrium, molecules of carbon dioxide in the gas phase can still dissolve in the liquid phase if they strike the surface and are captured. Similarly, molecules of carbon dioxide can escape from the liquid phase. What is the entropy change of the universe, $\Delta$S_uni_v, for the dissolution of carbon dioxide under these conditions?

Accepted Answer

At equilibrium, the system has reached a state of maximum entropy and there is no net change in entropy of the system or the universe. Therefore, the entropy change of the universe is zero.

Question 18

The following figures represent distributions of gas molecules between two containers connected by an open tube. In which figure is the entropy of the system maximized?

Accepted Answer

The entropy of the system is maximized when the gas molecules are distributed equally between the two containers. In figure D, the distribution of gas molecules is the most uniform and symmetrical between the two containers, indicating maximum entropy.

Question 19

Which of the following must be true for a spontaneous exothermic process?

Accepted Answer

The text in the choices seems to be corrupted or incorrectly formatted, making it difficult to interpret the specific scientific symbols or terms intended. However, based on the context of the question regarding a spontaneous exothermic process, the correct answer generally involves principles related to thermodynamics. For a spontaneous exothermic process, it is typically true that the change in the system's Gibbs free energy ($\Delta G$) is less than zero ($\Delta G < 0$) for the process to be spontaneous, and the process being exothermic implies that the change in enthalpy ($\Delta H$) is less than zero ($\Delta H < 0$). However, without clear text, it's challenging to directly match these principles to the given choices. The selection of "E" is based on a standard interpretation that for spontaneous processes, either the system's entropy increases, or the energy released to the surroundings is sufficient to drive the process, which aligns with general thermodynamic principles for spontaneous reactions.

Question 20

Indicate which of the following has the largest standard molar entropy (S S1U1P1$\circ$S1S1P0).

Accepted Answer

Entropy is a measure of the disorder or randomness in a system. Gaseous substances have higher entropy than liquids and solids because their molecules are more spread out and can move more freely. Among the options, CH₄(g) is the only gas, which means it has the highest standard molar entropy.

Quiz 17: Thermodynamics: Spontaneous and Nonspontaneous Reactions and Processes

When a molecule of ethylenediamine replaces two molecules of NH₃ in Co(NH₃) , the entropy of the system ________

Indicate which one of the following reactions most certainly results in a negative $\Delta$ S_sys.

Perfect crystals of carbon monoxide (CO) are difficult to prepare because the very small dipole moment allows a few molecules to align in a pattern such as CO OC CO instead of CO CO CO. If such disordered crystals were cooled to 0 K, what would be the value of their absolute entropy?

Before class, students were distributed throughout a classroom. When the bell rang, all the students sat down at three tables in the center of the room. The entropy of the class ________

Indicate which one of the following reactions most certainly does not result in a decrease in entropy.

Indicate which one of the following reactions results in a positive $\Delta$ S_sys.

The enthalpy of vaporization for toluene (C₇H₈) is 380.00 kJ/kg, and its boiling point is 110.6^$\circ$C. What is the entropy change when 0.75 mole of toluene vaporizes at 110.6^$\circ$C?

The following figures represent distributions of two types of gas molecules between two containers connected by an open tube. In which figure is the entropy of the system maximized?

Indicate which one of the following reactions results in a negative $\Delta$ S_sys.

Which of the following will have the greatest standard molar entropy (S^$\circ$) ?

At 0 K, the entropy of a perfect crystal is ________

Which of the processes A-D will lead to a positive change in the entropy of the system?

Which of the following processes will lead to a decrease in the entropy of the system?

Before class, students were seated at three tables. When the school alarm went off suddenly, all the students distributed throughout the room to collect their belongings. The entropy of the class ________

Which of the following graphs best depicts the entropy of a pure substance as the temperature is raised from its solid form through its liquid and gaseous forms?

The following figures represent distributions of gas molecules between two containers connected by an open tube. In which figure is the entropy of the system maximized?

Which of the following must be true for a spontaneous exothermic process?

Indicate which of the following has the largest standard molar entropy (S ^$\circ$) .

Quiz 17: Thermodynamics: Spontaneous and Nonspontaneous Reactions and Processes

When a molecule of ethylenediamine replaces two molecules of NH3 in Co(NH3) , the entropy of the system ________

Indicate which one of the following reactions most certainly results in a negative Δ\DeltaΔ Ssys.

Perfect crystals of carbon monoxide (CO) are difficult to prepare because the very small dipole moment allows a few molecules to align in a pattern such as CO OC CO instead of CO CO CO. If such disordered crystals were cooled to 0 K, what would be the value of their absolute entropy?

Before class, students were distributed throughout a classroom. When the bell rang, all the students sat down at three tables in the center of the room. The entropy of the class ________

Indicate which one of the following reactions most certainly does not result in a decrease in entropy.

Indicate which one of the following reactions results in a positive Δ\DeltaΔ Ssys.

The enthalpy of vaporization for toluene (C7H8) is 380.00 kJ/kg, and its boiling point is 110.6 ∘\circ∘ C. What is the entropy change when 0.75 mole of toluene vaporizes at 110.6 ∘\circ∘ C?

The following figures represent distributions of two types of gas molecules between two containers connected by an open tube. In which figure is the entropy of the system maximized?

Indicate which one of the following reactions results in a negative Δ\DeltaΔ Ssys.

Which of the following will have the greatest standard molar entropy (S ∘\circ∘ ) ?

At 0 K, the entropy of a perfect crystal is ________

Which of the processes A-D will lead to a positive change in the entropy of the system?

Which of the following processes will lead to a decrease in the entropy of the system?

Before class, students were seated at three tables. When the school alarm went off suddenly, all the students distributed throughout the room to collect their belongings. The entropy of the class ________

Which of the following graphs best depicts the entropy of a pure substance as the temperature is raised from its solid form through its liquid and gaseous forms?

The following figures represent distributions of gas molecules between two containers connected by an open tube. In which figure is the entropy of the system maximized?

Which of the following must be true for a spontaneous exothermic process?

Indicate which of the following has the largest standard molar entropy (S ∘\circ∘ ) .

When a molecule of ethylenediamine replaces two molecules of NH₃ in Co(NH₃) , the entropy of the system ________

Indicate which one of the following reactions most certainly results in a negative $\Delta$ S_sys.

Indicate which one of the following reactions results in a positive $\Delta$ S_sys.

The enthalpy of vaporization for toluene (C₇H₈) is 380.00 kJ/kg, and its boiling point is 110.6^$\circ$C. What is the entropy change when 0.75 mole of toluene vaporizes at 110.6^$\circ$C?

Indicate which one of the following reactions results in a negative $\Delta$ S_sys.

Which of the following will have the greatest standard molar entropy (S^$\circ$) ?

Indicate which of the following has the largest standard molar entropy (S ^$\circ$) .