Ther-Test-2

The specific heat of gas during the isothermal process becomes infinite.

During an isothermal process, the temperature change (ΔT) is zero.

The specific heat capacity (c) is given as ΔQ/nΔT. As ΔT is zero, the value would tend to infinity.

Thus, the correct answer is A, "Infinity".

An adiabatic process is characterized by the absence of any heat exchange with the surroundings.

Consequently, no heat is gained or lost during this process, thus the heat content of the system remains constant.

Therefore, the correct response is D, "The system's heat content".

The specific heat of a substance is directly proportional to the heat (Q) absorbed or released.

In the graph, if the heat absorbed by substance C (Qc) is greater than substances A and B, it implies that substance C has higher specific heat.

Hence, the correct answer is C, "Substance C".

Molar specific heat (C) is defined as the amount of heat (Q) absorbed or released by one mole of a substance for a unit change in temperature (ΔT).

Its formula is C = Q/nΔT, where n is the number of moles. Consequently, the unit of molar specific heat is 'Joules per mole per Kelvin' (J mol^-1 K^-1).

Thus, the correct answer is C, "Joules per mole per Kelvin".

• The heat capacity at constant pressure (Cp) is always greater than the heat capacity at constant volume (Cv) for gases.
• This difference is given by the formula Cp – Cv = R, where R is the universal gas constant.
• The value of R is 8.314 J mol^-1 K^-1.
• Therefore, the correct answer is D, 8.314.

• The relationship between heat (Q), work (W), and internal energy (U) is given by the equation Q = ΔU + W, where ΔU represents change in internal energy.
• In this case, we can rearrange the formula to find the final internal energy Uf as Uf = Q + Ui - W.
• Plugging known values gives us Uf = -40J + 70J - 20J = 50J.
• Thus, the correct answer is A, 50 J.

• An isolated system does not interact with its surroundings, meaning there's no exchange of heat (Q) or work (W).
• As such, the change in internal energy (ΔU) of an isolated system is zero, making the internal energy constant.
• Therefore, the correct answer is B, "It remains constant".

• Try to recall the First Law of Thermodynamics which describes the relationship between heat transfer (Q), change in internal energy (ΔU), and work done (W).
• In an isothermal process, the temperature remains constant, so what happens to the added heat energy if not used in increasing the temperature or internal energy?

• To raise a substance's temperature one degree, you need a certain amount of heat.
• Given that their mass, initial temperature and absorbed heat are the same, what characteristic can cause the samples to reach different final temperatures?

• A heat capacity ratio, or adiabatic index (γ), is the ratio of constant pressure heat capacity (Cp) to constant volume heat capacity (Cv).
• Given the nature of different types of gases, which gas type would logically have the highest ratio?

• Recall the heat capacity ratio (γ) equation, which states γ = Cp/Cv.
• For all gases, γ is greater than 1. What does this imply about the relationship between Cp and Cv?

• Consider the definitions of heat, work, and internal energy.
• Which of these terms refers to the energy that a system possesses due to the motion and interaction of its particles?

• Remember that in an isochoric process, the volume remains constant and there is no work done.
• With this in mind, how does the first law of thermodynamics (Q = W + ∆U) change when applying to an isochoric process?

• Consider the definitions of the different terms given in the options.
• Think about which term refers to the quantity of heat required to change the temperature of a certain mass of a substance by a specific degree.

• Understand that the ratio of Cv to Cp is a key concept in thermodynamics.
• Given the properties and behavior of gases, what would logically be the ratio of the specific heat at constant volume to the specific heat at constant pressure?

• Remember that absolute zero is the lowest theoretically possible temperature, where the motion of particles that constitutes heat is minimal.
• Given this knowledge, which of the options accurately represent absolute zero?

• Revisit the basic laws of thermodynamics, particularly the first law which relates heat, work, and changes in internal energy.
• With this knowledge, solve for the amount of heat supplied when the work done and the change in internal energy are known.

• Examine the characteristics of cyclic processes in thermodynamics.
• Keeping these characteristics in mind, derive a conclusion about the change in internal energy in both systems A and B.

• Understand the properties and characteristics of each process listed in the options.
• Identify the process where the temperature, and hence the internal energy, remains constant.

• Understand the principles of each of the laws of thermodynamics.
• Consider the law which defines the limits of conversion of heat energy into work.