Question 1

For a particular process q = -17 kJ and w = 21 kJ.Which of the following statements is false?

Accepted Answer

B

Question 2

Consider a gas in a 1.0 L bulb at STP that is connected via a valve to another bulb that is initially evacuated.Answer the following concerning what occurs when the valve between the two bulbs is opened.
-What is true about the value of $\Delta$E?

Accepted Answer

Since the initial pressure of the gas in the first bulb is at STP, the pressure is 1 atm and the temperature is 273 K. When the valve is opened, the gas will expand into the second bulb and reach equilibrium, which means it will also have a pressure of 1 atm and a temperature of 273 K. Therefore, both bulbs have the same temperature and pressure, and there is no difference to drive a net flow of gas between them. This means that the value of the Gibbs free energy change for the system is zero, which is represented by ∆G = ∆H - T∆S, where ∆H = 0 since there is no change in enthalpy and ∆S is also zero because both bulbs have the same temperature and entropy. Therefore, ∆G = 0, and the answer is B.

Question 3

For a particular process q = 20 kJ and w = 15 kJ.Which of the following statements is true?

Accepted Answer

C

Question 4

What is the kinetic energy of a 1.56-kg object moving at 94.0 km/hr?

Accepted Answer

The kinetic energy (KE) of an object can be calculated using the formula KE = 1/2 mv^2, where m is the mass in kilograms and v is the velocity in meters per second. First, convert the velocity from km/hr to m/s: 94.0 km/hr = 94.0 * 1000 m / 3600 s = 26.11 m/s. Then, plug the values into the formula: KE = 1/2 * 1.56 kg * (26.11 m/s)^2 = 532.7 J, or 5.32 kJ.

Question 5

When a system performs work on the surroundings,the work is reported with a negative sign.

Accepted Answer

According to the convention used in thermodynamics, work done by the system on the surroundings is reported with a negative sign. This is because work is the transfer of energy, and it is conventionally regarded as positive when the energy is transferred to the system and negative when it is transferred to the surroundings.

Question 6

Calculate the work associated with the expansion of a gas from 42.0 L to 79.0 L at a constant pressure of 14.0 atm.

Accepted Answer

The work done by the gas during expansion at constant pressure is calculated using the formula W = -PΔV. Here, P = 14.0 atm and ΔV = 79.0 L - 42.0 L = 37.0 L. Therefore, W = -14.0 atm * 37.0 L = -518 L·atm.

Question 7

According to the first law of thermodynamics,the energy of the universe is constant.Does this mean that $\Delta$E is always equal to zero?

Accepted Answer

The first law of thermodynamics states that the total energy of the universe is constant. However, this does not mean that the internal energy of a system always remains constant, as it can be affected by heat and work. Therefore, F1F1F1S1F1F1F10E does not always equal zero, and the correct option is C.

Question 8

Consider a gas in a 1.0 L bulb at STP that is connected via a valve to another bulb that is initially evacuated.Answer the following concerning what occurs when the valve between the two bulbs is opened.
-What is true about the value of w?

Accepted Answer

When the valve between the two bulbs is opened, the gas expands into the evacuated bulb without any external pressure being applied (since the second bulb is evacuated). This is an example of free expansion, where work done (w) by the gas is equal to zero because there is no external pressure to work against.

Question 9

A fuel-air mixture is placed in a cylinder fitted with a piston.The original volume is 0.310-L.When the mixture is ignited,gases are produced and 935 J of energy is released.To what volume will the gases expand against a constant pressure of 635 mmHg,if all the energy released is converted to work to push the piston?

Accepted Answer

To find the volume, use the work formula: W = -PΔV. Convert pressure to atm (635 mmHg = 0.835 atm) and energy to L·atm (935 J = 9.25 L·atm). Solve for ΔV: ΔV = W/P = 9.25 L·atm / 0.835 atm = 11.08 L. Add the initial volume: 0.310 L + 11.08 L = 11.39 L, which rounds to 11.4 L.

Question 10

Consider a gas in a 1.0 L bulb at STP that is connected via a valve to another bulb that is initially evacuated.Answer the following concerning what occurs when the valve between the two bulbs is opened.
-What is true about the value of $\Delta$H?

Accepted Answer

At STP, the pressure (P1) and temperature (T1) are known and constant. Additionally, the volume of the first bulb (V1) is known. Since the gas is connected via a valve to the second bulb, the volume of the system (Vtot) will increase but the temperature and pressure will remain constant. This means that according to the Ideal Gas Law, the initial moles of gas in bulb 1 (n1) will spread out into the two bulbs, with no net change in moles since the temperature and pressure are constant. Therefore, there is no change in internal energy (ΔU = 0) and the value of ΔH will be equal to the energy transferred as work (w), which is equal to zero since there is no change in pressure or volume from the initial state. Thus, ΔH = w = 0 and F1S1ΔH = 0 as well, so choice B is correct.

Question 11

Consider a gas in a 1.0 L bulb at STP that is connected via a valve to another bulb that is initially evacuated.Answer the following concerning what occurs when the valve between the two bulbs is opened.
-What is true about the value of q?

Accepted Answer

When the valve between the two bulbs is opened, the gas expands into the evacuated bulb without any exchange of heat with the surroundings, assuming ideal conditions. This is an example of a free expansion process, where no work is done on or by the system and no heat is transferred to or from the system, making q (the heat exchanged) equal to zero.

Question 12

Which of the following statements correctly describes the signs of q and w for the following exothermic process at P = 1 atm and T = 370 K? H₂O(g)$\to$ H₂O(l)

Accepted Answer

Since the process is exothermic (heat is being released), q must be negative. At constant pressure, the only work being done is expansion work, so w must be negative. Therefore, the correct statement is that q is negative and w is positive.

Question 13

A gas absorbs 0.0 J of heat and then performs 30.7 J of work.The change in internal energy of the gas is

Accepted Answer

The first law of thermodynamics states that the change in internal energy of a system is equal to the heat added to the system minus the work done by the system:

ΔU = Q - W

In this case, Q (heat added) is 0.0 J and W (work done) is 30.7 J. Therefore:

ΔU = 0.0 J - 30.7 J = -30.7 J

The negative sign indicates that the internal energy of the gas has decreased. So, the best choice is D.

Question 14

A state function does not depend on the system's past or future.

Accepted Answer

A state function only depends on the current state of the system, not its history or future behavior. Examples of state functions include temperature, pressure, and internal energy.

Question 15

A property that is independent of the pathway is called an intensive property.

Accepted Answer

A property that is independent of the pathway is called a state function or a state property, not an intensive property. Intensive properties are those that do not depend on the amount of matter present, such as temperature or density.

Question 16

One mole of an ideal gas is expanded from a volume of 1.00 liter to a volume of 8.93 liters against a constant external pressure of 1.00 atm.How much work (in joules)is performed on the surroundings? Ignore significant figures for this problem.(T = 300 K;1 L·atm = 101.3 J)

Accepted Answer

The work done on the surroundings can be calculated using the formula W = -PextΔV, where Pext is the external pressure and ΔV is the change in volume. Plugging in the values given, we get W = -(1.00 atm)(7.93 L) x (101.3 J/L·atm) = -803 J. Since the gas is doing work on the surroundings, the work done is negative. Therefore, the answer is B) 803 J.

Question 17

Calculate the work associated with the compression of a gas from 121.0 L to 80.0 L at a constant pressure of 13.1 atm.

Accepted Answer

The answer of Calculate the work associated with the compression...

Question 18

Which of the following statements is correct?

Accepted Answer

This is a correct statement according to the first law of thermodynamics. When an ideal gas expands against a constant external pressure, it does work on the surroundings and loses energy, which results in a decrease in the internal energy of the gas. Option A is incorrect because the internal energy increases when heat is added, not work. Option B is incorrect because work done on the system adds energy to the system and increases the internal energy, not decrease it. Option D is incorrect because only option C is correct. Therefore, option E is also incorrect as all statements are not false.

Question 19

Calculate the work for the expansion of CO₂ from 1.0 to 4.7 liters against a pressure of 1.0 atm at constant temperature.

Accepted Answer

The work done for the expansion of a gas at constant temperature and pressure is given by the formula: 
Work = -PΔV, where P is the pressure, ΔV is the change in volume, and the negative sign indicates that work is done on the system. 
In this case, ΔV = 4.7 L - 1.0 L = 3.7 L, and P = 1.0 atm. 
Substituting into the formula, we get: 
Work = - (1.0 atm) × (3.7 L) = -3.7 L·atm
Note that the negative sign indicates that work is done on the system, which makes sense because the gas is expanding against an external pressure. Therefore, the correct answer is (D).

Question 20

Which statement is true of a process in which one mole of a gas is expanded from state A to state B?

Accepted Answer

The amount of heat released or absorbed in a process (q) can depend on the path taken, as it is not a state function. State functions, like temperature, pressure, and volume, depend only on the state of the system, not on how the system reached that state. However, heat and work depend on the path taken to get from one state to another.

Quiz 6: Thermochemistry

For a particular process q = -17 kJ and w = 21 kJ.Which of the following statements is false?

Consider a gas in a 1.0 L bulb at STP that is connected via a valve to another bulb that is initially evacuated.Answer the following concerning what occurs when the valve between the two bulbs is opened. -What is true about the value of $\Delta$ E?

For a particular process q = 20 kJ and w = 15 kJ.Which of the following statements is true?

What is the kinetic energy of a 1.56-kg object moving at 94.0 km/hr?

When a system performs work on the surroundings,the work is reported with a negative sign.

Calculate the work associated with the expansion of a gas from 42.0 L to 79.0 L at a constant pressure of 14.0 atm.

According to the first law of thermodynamics,the energy of the universe is constant.Does this mean that $\Delta$ E is always equal to zero?

Consider a gas in a 1.0 L bulb at STP that is connected via a valve to another bulb that is initially evacuated.Answer the following concerning what occurs when the valve between the two bulbs is opened. -What is true about the value of w?

Consider a gas in a 1.0 L bulb at STP that is connected via a valve to another bulb that is initially evacuated.Answer the following concerning what occurs when the valve between the two bulbs is opened. -What is true about the value of $\Delta$ H?

Consider a gas in a 1.0 L bulb at STP that is connected via a valve to another bulb that is initially evacuated.Answer the following concerning what occurs when the valve between the two bulbs is opened. -What is true about the value of q?

Which of the following statements correctly describes the signs of q and w for the following exothermic process at P = 1 atm and T = 370 K? H₂O(g) $\to$ H₂O(l)

A gas absorbs 0.0 J of heat and then performs 30.7 J of work.The change in internal energy of the gas is

A state function does not depend on the system's past or future.

A property that is independent of the pathway is called an intensive property.

One mole of an ideal gas is expanded from a volume of 1.00 liter to a volume of 8.93 liters against a constant external pressure of 1.00 atm.How much work (in joules) is performed on the surroundings? Ignore significant figures for this problem.(T = 300 K;1 L·atm = 101.3 J)

Calculate the work associated with the compression of a gas from 121.0 L to 80.0 L at a constant pressure of 13.1 atm.

Which of the following statements is correct?

Calculate the work for the expansion of CO₂ from 1.0 to 4.7 liters against a pressure of 1.0 atm at constant temperature.

Which statement is true of a process in which one mole of a gas is expanded from state A to state B?

Quiz 6: Thermochemistry

For a particular process q = -17 kJ and w = 21 kJ.Which of the following statements is false?

Consider a gas in a 1.0 L bulb at STP that is connected via a valve to another bulb that is initially evacuated.Answer the following concerning what occurs when the valve between the two bulbs is opened. -What is true about the value of Δ\DeltaΔ E?

For a particular process q = 20 kJ and w = 15 kJ.Which of the following statements is true?

What is the kinetic energy of a 1.56-kg object moving at 94.0 km/hr?

When a system performs work on the surroundings,the work is reported with a negative sign.

Calculate the work associated with the expansion of a gas from 42.0 L to 79.0 L at a constant pressure of 14.0 atm.

According to the first law of thermodynamics,the energy of the universe is constant.Does this mean that Δ\DeltaΔ E is always equal to zero?

Consider a gas in a 1.0 L bulb at STP that is connected via a valve to another bulb that is initially evacuated.Answer the following concerning what occurs when the valve between the two bulbs is opened. -What is true about the value of w?

Consider a gas in a 1.0 L bulb at STP that is connected via a valve to another bulb that is initially evacuated.Answer the following concerning what occurs when the valve between the two bulbs is opened. -What is true about the value of Δ\DeltaΔ H?

Consider a gas in a 1.0 L bulb at STP that is connected via a valve to another bulb that is initially evacuated.Answer the following concerning what occurs when the valve between the two bulbs is opened. -What is true about the value of q?

Which of the following statements correctly describes the signs of q and w for the following exothermic process at P = 1 atm and T = 370 K? H2O(g) →\to→ H2O(l)

A gas absorbs 0.0 J of heat and then performs 30.7 J of work.The change in internal energy of the gas is

A state function does not depend on the system's past or future.

A property that is independent of the pathway is called an intensive property.

One mole of an ideal gas is expanded from a volume of 1.00 liter to a volume of 8.93 liters against a constant external pressure of 1.00 atm.How much work (in joules) is performed on the surroundings? Ignore significant figures for this problem.(T = 300 K;1 L·atm = 101.3 J)

Calculate the work associated with the compression of a gas from 121.0 L to 80.0 L at a constant pressure of 13.1 atm.

Which of the following statements is correct?

Calculate the work for the expansion of CO2 from 1.0 to 4.7 liters against a pressure of 1.0 atm at constant temperature.

Which statement is true of a process in which one mole of a gas is expanded from state A to state B?

Consider a gas in a 1.0 L bulb at STP that is connected via a valve to another bulb that is initially evacuated.Answer the following concerning what occurs when the valve between the two bulbs is opened. -What is true about the value of $\Delta$ E?

According to the first law of thermodynamics,the energy of the universe is constant.Does this mean that $\Delta$ E is always equal to zero?

Consider a gas in a 1.0 L bulb at STP that is connected via a valve to another bulb that is initially evacuated.Answer the following concerning what occurs when the valve between the two bulbs is opened. -What is true about the value of $\Delta$ H?

Which of the following statements correctly describes the signs of q and w for the following exothermic process at P = 1 atm and T = 370 K? H₂O(g) $\to$ H₂O(l)

Calculate the work for the expansion of CO₂ from 1.0 to 4.7 liters against a pressure of 1.0 atm at constant temperature.