Question 1

For a given transfer of energy,a greater change in disorder occurs when the temperature is high.

Accepted Answer

A greater change in disorder, or increase in entropy, occurs when energy is transferred at a lower temperature because the same amount of energy results in a proportionally larger change in entropy at lower temperatures.

Question 2

The change in molar entropy for vaporization of all liquids is about the same.

Accepted Answer

The change in molar entropy for vaporization of liquids is relatively constant, typically around 85-88 J/mol·K, because the process involves a similar increase in disorder or randomness when a liquid becomes a gas, regardless of the specific liquid.

Question 3

Calculate the change in molar entropy when the pressure of argon is allowed to double isothermally (assume ideal behavior). A)+1.39 J.K^-1.mol^-1 B)(-1.39 J.K^-1.mol^-1) C)(-4.16 J.K^-1.mol^-1) D)(-5.76 J.K^-1.mol^-1) E)+5.76 J.K^-1.mol^-1

Accepted Answer

D

Question 4

The temperature of 2.00 mol Ne(g)is increased from 25S1U1P1$\circ$S1S1P0C to 200S1U1P1$\circ$S1S1P0C at constant pressure.Calculate the change in the entropy of neon (assume ideal behavior). A)+7.68 J.K^-1 B)+19.2 J.K^-1 C)(-7.68 J.K^-1) D)(-19.2 J.K^-1) E)+9.60 J.K^-1

Accepted Answer

The change in entropy of neon can be calculated using the formula: ΔS = nCp ln(Tf/Ti), where n is the number of moles, Cp is the molar heat capacity at constant pressure, and Tf and Ti are the final and initial temperatures in Kelvin, respectively.

First, we need to convert the temperatures from Celsius to Kelvin:
Ti = 25 + 273.15 = 298.15 K
Tf = 200 + 273.15 = 473.15 K

The molar heat capacity of neon gas at constant pressure is Cp = (5/2)R, where R is the gas constant. Therefore, Cp = (5/2) * 8.314 J/(mol*K) = 20.785 J/(mol*K)

Substituting the values into the formula, we get:
ΔS = 2 mol * 20.785 J/(mol*K) * ln(473.15 K/298.15 K) = 19.2 J/(K*mol)

Therefore, the best choice is B.

Question 5

All entropies of fusion are positive.

Accepted Answer

Entropy of fusion is the change in entropy when a substance changes from its solid state to its liquid state at its melting point. As heat is added to the solid, its particles gain energy and become more disordered in the liquid state. Therefore, the entropy of fusion is always positive.

Question 6

Calculate the standard entropy of vaporization of ethanol at its boiling point,352 K.The standard molar enthalpy of vaporization of ethanol at its boiling point is 40.5 J.K^-1.mol^-1. A)+40.5 J.K^-1.mol^-1 B)+115 J.K^-1.mol^-1 C)(-40.5 J.K^-1.mol^-1) D)+513 J.K^-1.mol^-1 E)(-115 J.K^-1.mol^-1)

Accepted Answer

The standard entropy of vaporization is calculated using the formula ΔS_vap = ΔH_vap / T. Here, ΔH_vap = 40.5 J/mol and T = 352 K, so ΔS_vap = 40.5 J/mol / 352 K = 0.115 J/K/mol, which is approximately +115 J/K/mol.

Question 7

The molar entropy of silver at 298 K is equal to the area under the curve obtained by plotting (from T = 0 to T = 298 K) A)C_P versus T. B)lnC_P versus T. C)ln(C_P/T)versus T. D)C_P/T versus T. E)C_P versus 1/T.

Accepted Answer

The molar entropy change is calculated by integrating C_P/T with respect to T from 0 to 298 K.

Question 8

Consider the following processes (treat all gases as ideal).
1.The pressure of 1 mole of oxygen gas is allowed to double isothermally.
2.Carbon dioxide is allowed to expand isothermally to 10 times its original volume.
3.The temperature of 1 mol of helium is increased 25°C at constant pressure.
4.Nitrogen gas is compressed isothermally to half its original volume.
5.A glass of water loses 100 J of energy reversibly at 30°C.
Which of these processes lead(s) to an increase in entropy? 
A)1 and 4
B)5
C)3 and 5
D)2 and 3
E)1 and 2

Accepted Answer

The answer of Consider the following processes (treat all gases...

Question 9

What is the change in entropy when the pressure of an ideal gas is increased at constant temperature? Choose from +,0,-.

Accepted Answer

The answer of What is the change in entropy when...

Question 10

Use Trouton's constant to estimate the enthalpy of condensation of diethyl ether,which boils at 309 K. A)(-26 kJ.mol^-1) B)+26 kJ.mol^-1 C)(-275 kJ.mol^-1) D)(-85 kJ.mol^-1) E)+85 kJ.mol^-1

Accepted Answer

Trouton's constant is approximately 85 J/mol·K for many liquids. The enthalpy of vaporization (and thus condensation) can be estimated as ΔHvap = T * ΔSvap, where ΔSvap is Trouton's constant. For diethyl ether at 309 K, ΔHvap ≈ 309 K * 85 J/mol·K = 26,265 J/mol ≈ 26 kJ/mol. Since condensation is the reverse of vaporization, the enthalpy of condensation is negative, thus -26 kJ/mol.

Question 11

Use Trouton's constant to estimate the enthalpy of vaporization of diethyl ether,which boils at 309 K. A)+85 kJ.mol^-1 B)+26 kJ.mol^-1 C)+275 kJ.mol^-1 D)(-85 kJ.mol^-1) E)+3.6 kJ.mol^-1

Accepted Answer

Trouton's rule states that the entropy of vaporization is approximately 85 J/mol·K for many liquids. Using this, ΔHvap = T * ΔSvap = 309 K * 85 J/mol·K = 26,265 J/mol ≈ 26 kJ/mol.

Question 12

The enthalpy of fusion of H₂O(s)at its normal melting point is 6.01 kJ.mol^-1.The entropy change for freezing 1 mol of water at this temperature is A)+20.2 J.K^-1.mol^-1 B)0 J.K^-1.mol^-1 C)(-20.2 J.K^-1.mol^-1) D)+22.0 J.K^-1.mol^-1 E)(-22.0 J.K^-1.mol^-1)

Accepted Answer

The answer of The enthalpy of fusion of H₂O(s)at its...

Question 13

Calculate the normal boiling point of chloroform,given that the standard entropy and enthalpy of vaporization of chloroform is +93.7 J.K^-1.mol^-1 and 31.4 J.K^-1.mol^-1

Accepted Answer

The answer of Calculate the normal boiling point of chloroform,given...

Question 14

Calculate the standard entropy of fusion of ethanol at its melting point,159 K.The standard molar enthalpy of fusion of ethanol at its melting point is 5.02 J.K^-1.mol^-1 A)(-5.02 J.K^-1.mol^-1) B)(-31.6 J.K^-1.mol^-1) C)+5.02 J.K^-1.mol^-1 D)+31.6 J.K^-1.mol^-1 E)(-44.0 J.K^-1.mol^-1)

Accepted Answer

The answer of Calculate the standard entropy of fusion of...

Question 15

Calculate the change in entropy of a large pail of water after 200 J of energy is reversibly transferred to the water at 20S1U1P1$\circ$S1S1P0C. A)(-0.733 J.K^-1) B)(+0.683 J.K^-1) C)(-0.683 J.K^-1) D)(+0.733 J.K^-1) E)(-200 J.K^-1)

Accepted Answer

The change in entropy (ΔS) is calculated using the formula ΔS = Q/T, where Q is the heat added and T is the temperature in Kelvin. Convert 20°C to Kelvin (293 K) and calculate ΔS = 200 J / 293 K = +0.683 J.K^-1.

Question 16

The cooling of a hot metal is accompanied by an increase in entropy.

Accepted Answer

During the cooling of a hot metal, the molecules within the metal lose thermal energy and move from a state of high order (i.e. close together and vibrating rapidly) to a state of low order (i.e. further apart and vibrating less). This increase in disorder and randomness corresponds to an increase in entropy, which is a measure of the degree of randomness or disorder within a system. Therefore, the statement is true.

Question 17

Calculate the standard entropy of condensation of chloroform at its boiling point,335 K.The standard molar enthalpy of vaporization of chloroform at its boiling point is 31.4 J.K^-1.mol^-1. A)(-31.3 J.K^-1.mol^-1) B)+93.7 J.K^-1.mol^-1 C)(-93.7 J.K^-1.mol^-1) D)+31.4 J.K^-1.mol^-1 E)+506 J.K^-1.mol^-1

Accepted Answer

The standard entropy of condensation is equal to the negative of the standard entropy of vaporization. The standard entropy of vaporization is given by the equation:$$\Delta S_{vap} = \frac{\Delta H_{vap}}{T}$$where $\Delta H_{vap}$ is the standard molar enthalpy of vaporization and T is the boiling point. Substituting the given values into this equation, we get:$$\Delta S_{vap} = \frac{31.4 J.K^{-1}.mol^{-1}}{335 K} = 0.0937 J.K^{-1}.mol^{-1}$$Therefore, the standard entropy of condensation is:$$\Delta S_{cond} = -\Delta S_{vap} = -0.0937 J.K^{-1}.mol^{-1} = -93.7 J.K^{-1}.mol^{-1}$$

Question 18

Consider the following processes (treat all gases as ideal).
1.The pressure of 1 mol of oxygen gas is allowed to double isothermally.
2.Carbon dioxide is allowed to expand isothermally to 10 times its original volume.
3.The temperature of 1 mol of helium is increased 25°C at constant pressure.
4.Nitrogen gas is compressed isothermally to half its original volume.
5.A glass of water loses 100 J of energy reversibly at 30°C.
Which of these processes lead(s) to a decrease in entropy? 
A)1 and 2
B)2
C)3 and 4
D)1,4,and 5
E)1 and 3

Accepted Answer

Entropy decreases when a system loses energy or when the volume of a gas decreases isothermally. In process 1, the volume decreases as pressure doubles isothermally, leading to a decrease in entropy. In process 4, compressing nitrogen gas to half its volume isothermally also decreases entropy. In process 5, the glass of water losing energy reversibly at a constant temperature results in a decrease in entropy.

Question 19

Calculate the change in molar entropy when 2.00 mol of ozone are compressed isothermally to one quarter of its original volume.Treat ozone as an ideal gas. A)(-23.1 J.K^-1) B)(-10.0 J.K^-1) C)(-1.39 J.K^-1) D)+10.0 J.K^-1 E)+23.1 J.K^-1

Accepted Answer

The change in molar entropy for an ideal gas during isothermal compression is given by ΔS = nRln(Vf/Vi). Here, Vf/Vi = 1/4, n = 2.00 mol, and R = 8.314 J/mol·K. Calculating gives ΔS = 2 * 8.314 * ln(1/4) = -23.1 J/K.

Question 20

The molar heat capacity of Cu(s)at 1 atm pressure has been measured over a range of temperatures from close to 0 K to 400 K.Describe how you would obtain the standard molar entropy of Cu(s)at 298 K.

Accepted Answer

The answer of The molar heat capacity of Cu(s)at 1...

Quiz 9: Thermodynamics: The Second and Third Laws

For a given transfer of energy,a greater change in disorder occurs when the temperature is high.

The change in molar entropy for vaporization of all liquids is about the same.

Calculate the change in molar entropy when the pressure of argon is allowed to double isothermally (assume ideal behavior) .

The temperature of 2.00 mol Ne(g) is increased from 25^$\circ$C to 200^$\circ$C at constant pressure.Calculate the change in the entropy of neon (assume ideal behavior) .

All entropies of fusion are positive.

Calculate the standard entropy of vaporization of ethanol at its boiling point,352 K.The standard molar enthalpy of vaporization of ethanol at its boiling point is 40.5 J.K^-1.mol^-1.

The molar entropy of silver at 298 K is equal to the area under the curve obtained by plotting (from T = 0 to T = 298 K)

What is the change in entropy when the pressure of an ideal gas is increased at constant temperature? Choose from +,0,-.

Use Trouton's constant to estimate the enthalpy of condensation of diethyl ether,which boils at 309 K.

Use Trouton's constant to estimate the enthalpy of vaporization of diethyl ether,which boils at 309 K.

The enthalpy of fusion of H₂O(s) at its normal melting point is 6.01 kJ.mol^-1.The entropy change for freezing 1 mol of water at this temperature is

Calculate the normal boiling point of chloroform,given that the standard entropy and enthalpy of vaporization of chloroform is +93.7 J.K^-1.mol^-1 and 31.4 J.K^-1.mol^-1

Calculate the standard entropy of fusion of ethanol at its melting point,159 K.The standard molar enthalpy of fusion of ethanol at its melting point is 5.02 J.K^-1.mol^-1

Calculate the change in entropy of a large pail of water after 200 J of energy is reversibly transferred to the water at 20^$\circ$C.

The cooling of a hot metal is accompanied by an increase in entropy.

Calculate the standard entropy of condensation of chloroform at its boiling point,335 K.The standard molar enthalpy of vaporization of chloroform at its boiling point is 31.4 J.K^-1.mol^-1.

Calculate the change in molar entropy when 2.00 mol of ozone are compressed isothermally to one quarter of its original volume.Treat ozone as an ideal gas.

The molar heat capacity of Cu(s)at 1 atm pressure has been measured over a range of temperatures from close to 0 K to 400 K.Describe how you would obtain the standard molar entropy of Cu(s)at 298 K.

Quiz 9: Thermodynamics: The Second and Third Laws

For a given transfer of energy,a greater change in disorder occurs when the temperature is high.

The change in molar entropy for vaporization of all liquids is about the same.

Calculate the change in molar entropy when the pressure of argon is allowed to double isothermally (assume ideal behavior) .

The temperature of 2.00 mol Ne(g) is increased from 25 ∘\circ∘ C to 200 ∘\circ∘ C at constant pressure.Calculate the change in the entropy of neon (assume ideal behavior) .

All entropies of fusion are positive.

Calculate the standard entropy of vaporization of ethanol at its boiling point,352 K.The standard molar enthalpy of vaporization of ethanol at its boiling point is 40.5 J.K-1.mol-1 .

The molar entropy of silver at 298 K is equal to the area under the curve obtained by plotting (from T = 0 to T = 298 K)

What is the change in entropy when the pressure of an ideal gas is increased at constant temperature? Choose from +,0,-.

Use Trouton's constant to estimate the enthalpy of condensation of diethyl ether,which boils at 309 K.

Use Trouton's constant to estimate the enthalpy of vaporization of diethyl ether,which boils at 309 K.

The enthalpy of fusion of H2O(s) at its normal melting point is 6.01 kJ.mol-1.The entropy change for freezing 1 mol of water at this temperature is

Calculate the normal boiling point of chloroform,given that the standard entropy and enthalpy of vaporization of chloroform is +93.7 J.K-1.mol-1 and 31.4 J.K-1.mol-1

Calculate the standard entropy of fusion of ethanol at its melting point,159 K.The standard molar enthalpy of fusion of ethanol at its melting point is 5.02 J.K-1.mol-1

Calculate the change in entropy of a large pail of water after 200 J of energy is reversibly transferred to the water at 20 ∘\circ∘ C.

The cooling of a hot metal is accompanied by an increase in entropy.

Calculate the standard entropy of condensation of chloroform at its boiling point,335 K.The standard molar enthalpy of vaporization of chloroform at its boiling point is 31.4 J.K-1.mol-1 .

Calculate the change in molar entropy when 2.00 mol of ozone are compressed isothermally to one quarter of its original volume.Treat ozone as an ideal gas.

The molar heat capacity of Cu(s)at 1 atm pressure has been measured over a range of temperatures from close to 0 K to 400 K.Describe how you would obtain the standard molar entropy of Cu(s)at 298 K.

The temperature of 2.00 mol Ne(g) is increased from 25^$\circ$C to 200^$\circ$C at constant pressure.Calculate the change in the entropy of neon (assume ideal behavior) .

Calculate the standard entropy of vaporization of ethanol at its boiling point,352 K.The standard molar enthalpy of vaporization of ethanol at its boiling point is 40.5 J.K^-1.mol^-1.

The enthalpy of fusion of H₂O(s) at its normal melting point is 6.01 kJ.mol^-1.The entropy change for freezing 1 mol of water at this temperature is

Calculate the normal boiling point of chloroform,given that the standard entropy and enthalpy of vaporization of chloroform is +93.7 J.K^-1.mol^-1 and 31.4 J.K^-1.mol^-1

Calculate the standard entropy of fusion of ethanol at its melting point,159 K.The standard molar enthalpy of fusion of ethanol at its melting point is 5.02 J.K^-1.mol^-1

Calculate the change in entropy of a large pail of water after 200 J of energy is reversibly transferred to the water at 20^$\circ$C.

Calculate the standard entropy of condensation of chloroform at its boiling point,335 K.The standard molar enthalpy of vaporization of chloroform at its boiling point is 31.4 J.K^-1.mol^-1.