Question 1

A container of ideal gas has a movable frictionless piston.This container is placed in a very large water bath and slowly compressed so that the temperature of the gas remains constant and equal to the temperature of the water.Which of the following statements about this gas are true for this process? (There may be more than one correct choice.)

Accepted Answer

,C

Question 2

When a fixed amount of ideal gas goes through an isobaric expansion

Accepted Answer

In an isobaric expansion, the pressure of the gas remains constant while its volume increases. As the gas expands, it does work on its surroundings, which means that the internal energy of the gas decreases. To conserve energy, this decrease in internal energy must be balanced by an increase in the kinetic energy of the gas molecules, i.e. an increase in temperature. Therefore, in an isobaric expansion, the temperature of the gas must increase.

Question 3

The process shown in the T-V diagram in the figure is an

Accepted Answer

The process shown in the T-V diagram is an isothermal compression because the temperature remains constant during the process while the volume decreases.

Question 4

When a solid melts

Accepted Answer

When a solid melts, it absorbs heat energy from its surroundings in order to break down its crystal lattice structure and transition into a liquid state. Therefore, heat energy enters the substance.

Question 5

When a fixed amount of ideal gas goes through an adiabatic expansion

Accepted Answer

In an adiabatic expansion, there is no exchange of heat between the gas and its surroundings. Therefore, the internal (thermal) energy of the gas does not change, but the gas does work against its surroundings, which causes a decrease in its temperature and pressure. The pressure may increase under certain conditions, but it is not a necessary outcome of adiabatic expansion.

Question 6

An ideal gas is compressed in a well-insulated chamber using a well-insulated piston.This process is

Accepted Answer

Since the chamber is well-insulated, there is no heat transfer between the gas and the surroundings, making the process adiabatic.

Question 7

An ideal gas increases in temperature from 22°C to 42°C by two different processes.In one process,the temperature increases at constant volume,and in the other process the temperature increases at constant pressure.Which of the following statements about this gas are correct? (There may be more than one correct choice.)

Accepted Answer

,C

Question 8

(a)Internal human body temperature is often stated to be normal at 98.6°F. What is this temperature on the Celsius and Kelvin scales?
(b)Gallium boils at 2205°C.What is the corresponding temperature in the Fahrenheit and Kelvin scales?
(c)The boiling point of liquid nitrogen is 77.0 K.What is the corresponding temperature in the Fahrenheit and Celsius scales?

Accepted Answer

The answer of (a)Internal human body temperature is often stated...

Question 9

It is a well-known fact that water has a higher specific heat than iron.Now,consider equal masses of water and iron that are initially in thermal equilibrium.The same amount of heat,30 calories,is added to each one.Which statement is true?

Accepted Answer

Since water has a higher specific heat than iron, it requires more heat to change its temperature by the same amount. Therefore, when the same amount of heat is added to both, the iron, having a lower specific heat, will warm up more than the water, breaking the thermal equilibrium and making the iron warmer.

Question 10

The process shown in the pV diagram in the figure is

Accepted Answer

The answer of The process shown in the pV diagram...

Question 11

An adiabatic compression is performed on an ideal gas.The final pressure is equal to 0.560 times the initial pressure and the final volume equals 1.50 times the initial volume.What is the adiabatic constant for the gas?

Accepted Answer

The adiabatic compression equation is given by:

$P_fV_f^{\gamma}=P_iV_i^{\gamma}$

where $P_f$ and $V_f$ are final pressure and volume,respectively and $P_i$ and $V_i$ are initial pressure and volume respectively.

Given that:

$P_f=0.56P_i$ and $V_f=1.50V_i$

Substituting these values in the adiabatic compression equation:

$0.56P_i	imes(1.50V_i)^{\gamma}=P_iV_i^{\gamma}$

Simplifying:

$0.56	imes1.5^{\gamma}=1$

Taking natural logarithm on both sides:

$\ln(0.56	imes1.5^{\gamma})=\ln(1)$

$\ln(0.56)+\gamma\ln(1.5)=0$

$\gamma=\frac{-\ln(0.56)}{\ln(1.5)}\approx1.43$

Therefore, the adiabatic constant for the gas is 1.43 which is option B.

Question 12

A quantity of ideal gas requires 800 kJ to raise the temperature of the gas by 10.0 K when the gas is maintained at constant volume. The same quantity of gas requires 900 kJ to raise the temperature of the gas by 10.0 K when the gas is maintained at constant pressure. What is the adiabatic constant γ for this gas?

Accepted Answer

We can use the specific heat ratio formula to solve for γ:

γ = Cp/Cv

where Cp is the specific heat at constant pressure and Cv is the specific heat at constant volume.

From the problem, we have:

ΔQv = 800 kJ
ΔTv = 10.0 K
ΔQp = 900 kJ
ΔTp = 10.0 K

We know that:

ΔQ = nCΔT

where n is the number of moles of gas and C is the molar specific heat capacity. For a monatomic ideal gas, we have:

Cv = (3/2)R
Cp = (5/2)R

where R is the gas constant.

Using ΔQv and ΔTv, we can solve for Cv:

ΔQv = nCvΔTv
Cv = ΔQv/(nΔTv) = (800 kJ)/(n(10.0 K)) = (80 kJ/mol*K)

Similarly, using ΔQp and ΔTp, we can solve for Cp:

ΔQp = nCpΔTp
Cp = ΔQp/(nΔTp) = (900 kJ)/(n(10.0 K)) = (90 kJ/mol*K)

Now we can calculate γ:

γ = Cp/Cv = (5/2)R/(3/2)R = 5/3 ≈ 1.67

Therefore, the answer is B.

Question 13

When a gas undergoes an isothermal process,there is

Accepted Answer

In an isothermal process, the temperature of the gas remains constant by definition. Changes in pressure, volume, work done, and heat added can occur to maintain the constant temperature.

Question 14

The process shown in the pV diagram in the figure is an

Accepted Answer

The answer of The process shown in the pV diagram...

Question 15

When a vapor condenses

Accepted Answer

When a vapor condenses, it changes from a gas phase to a liquid phase, releasing heat energy in the process. This is because the molecules in the vapor lose energy and move closer together to form a liquid, which involves the release of heat.

Question 16

When a fixed amount of ideal gas goes through an isochoric process

Accepted Answer

In an isochoric process, the volume of the gas remains constant. Since work done by a gas is given by W = PΔV (where P is pressure and ΔV is the change in volume), if the volume does not change (ΔV = 0), no work is done by the gas. Choices A, C, D, and E are not necessarily true for an isochoric process, as changes in internal energy, heat exchange, and temperature or pressure depend on specific conditions and energy transfers, not solely on the process being isochoric.

Question 17

Heat is added to a pure substance in a closed container at a constant rate.The figure shows a graph of the temperature of the substance as a function of time.If L_f = latent heat of fusion and L_v = latent heat of vaporization,what is the value of the ratio L_v / L_f for this substance?

Accepted Answer

The answer of Heat is added to a pure substance...

Question 18

A thermally isolated system is made up of a hot piece of aluminum and a cold piece of copper; the aluminum and the copper are in thermal contact.The specific heat of aluminum is more than double that of copper.Which object experiences the greater temperature change during the time the system takes to reach thermal equilibrium?

Accepted Answer

The answer of A thermally isolated system is made up...

Question 19

When a fixed amount of ideal gas goes through an isothermal expansion

Accepted Answer

During an isothermal expansion, the temperature of the gas remains constant. As a result, the internal (thermal) energy of the gas does not change since it is solely dependent on temperature. Therefore, choice A is correct. Choices B and C are incorrect since work is done by the gas and heat may enter or leave the gas in order to maintain the constant temperature. Choice D is also incorrect since the temperature remains constant during the expansion. Choice E is also incorrect since the pressure and volume of the gas are inversely proportional according to Boyle's Law, so an increase in volume during the expansion would lead to a decrease in pressure.

Question 20

Heat is added to a 2.0 kg piece of ice at a rate of 793.0 kW.How long will it take for the ice to melt if it was initially at 0.00°C? (The latent heat of fusion for water is 334 kJ/kg and its latent heat of vaporization is 2260 kJ/kg.)

Accepted Answer

The answer of Heat is added to a 2.0 kg...

Quiz 20: Energy Transferred Thermally