Description : Specific __________ does not change during phase change at constant temperature and pressure. (A) Entropy (B) Gibbs energy (C) Internal energy (D) Enthalpy
Last Answer : (B) Gibbs energy
Description : Joule-Thomson effect i.e., a throttling process is a constant __________ process. (A) Entropy (B) Temperature (C) Internal energy (D) Enthalpy
Last Answer : (D) Enthalpy
Description : High pressure steam is expanded adiabatically and reversibly through a well insulated turbine, which produces some shaft work. If the enthalpy change and entropy change across the turbine are represented by ΔH and ΔS respectively for this process: ... (C) Δ H ≠ 0 and ΔS ≠ 0 (D) Δ H = 0 and ΔS ≠ 0
Last Answer : (B) Δ H ≠ 0 and ΔS = 0
Description : Which of the following occurs in a reversible polytrophic process? a. Enthalpy remains constant b. Internal energy does not change c. Some heat transfer occurs d. Entropy remains constant
Last Answer : Some heat transfer occurs
Description : According to first law of thermodynamics (a) work done by a system is equal to heat transferred by the system (b) total internal energy of a system during a process remains constant ( ... , enthalpy and entropy during a process remain constant (d) total energy of a system remains constant
Last Answer : Answer : d
Description : During Joule-Thomson expansion of gases (A) Enthalpy remains constant (B) Entropy remains constant (C) Temperature remains constant (D) None of these
Last Answer : (A) Enthalpy remains constant
Description : For an incompressible fluid, the __________ is a function of both pressure as well as temperature. (A) Internal energy (B) Enthalpy (C) Entropy (D) All (A), (B) & (C)
Last Answer : (B) Enthalpy
Description : What are the names given to constant temperature, constant pressure, constant volume, constant internal energy, constant enthalpy, and constant entropy processes.
Last Answer : Isothermal, isochroic, isobaric, free expression, throttling and adiabatic processes respectively.
Description : Change in enthalpy in a closed system is equal to heat transferred if the reversible process takes place at constant (a) pressure (b) temperature (c) volume (d) internal energy (e) entropy.
Last Answer : Answer : a
Description : Specific __________ does not change during a phase change (e.g. sublimation, melting, vaporisation etc.). (A) Entropy (B) Internal energy (C) Enthalpy (D) Gibbs free energy
Last Answer : (D) Gibbs free energy
Description : What happens to the internal energy of water at reference temperature where enthalpy is zero? a. Becomes negative b. Becomes positive c. Remains constant d. Cannot be defined
Last Answer : Becomes negative
Description : Mollier diagram is a plot of (A) Temperature vs. enthalpy (B) Temperature vs. enthalpy (C) Entropy vs. enthalpy (D) Temperature vs. internal energy
Last Answer : (C) Entropy vs. enthalpy
Description : If heat be exchanged in a reversible manner, which of the following property of the working substance will change accordingly (a) temperature (b) enthalpy (c) internal energy (d) entropy (e) all of the above.
Description : Which of the following is the property of a system (a) pressure and temperature (b) internal energy (c) volume and density (d) enthalpy and entropy (e) all of the above.
Last Answer : Answer : e
Description : Pick out the correct statement. (A) Like internal energy and enthalpy, the absolute value of standard entropy for elementary substances is zero (B) Melting of ice involves increase in enthalpy and ... of an ideal gas depends only on its pressure (D) Maximum work is done under reversible conditions
Last Answer : (D) Maximum work is done under reversible conditions
Description : Isentropic process means a constant __________ process. (A) Enthalpy (B) Pressure (C) Entropy (D) None of these
Last Answer : (C) Entropy
Description : Throttling (Joule-Thomson effect) process is a constant __________ process. (A) Enthalpy (B) Entropy (C) Pressure (D) None of these
Last Answer : (A) Enthalpy
Description : Throttling process is a/an __________ process. (A) Reversible and isothermal (B) Irreversible and constant enthalpy (C) Reversible and constant entropy (D) Reversible and constant enthalpy
Last Answer : (B) Irreversible and constant enthalpy
Description : If the rate of a chemical reaction becomes slower at a given temperature, then the (A) Initial concentration of the reactants remains constant (B) Free energy of activation is lower (C) Entropy changes (D) Free energy of activation is higher
Last Answer : (D) Free energy of activation is higher
Description : What is defined as the sum of the system’s internal energy and the product of its pressure and volume? a. Entropy. b. Enthalpy. c. Free energy. d. Potential energy.
Last Answer : b. Enthalpy.
Description : Entropy is the measure of: a. The internal energy of a gas b. The heat capacity of a substance c. Randomness or disorder d. The change of enthalpy of a system
Last Answer : Randomness or disorder
Description : What is the measure of the energy that is no longer available to perform useful work within the current environment? a. enthalpy b. entropy c. internal energy d. latent heat
Last Answer : entropy
Description : What is known as the total heat and heat content at various times in the history? a. enthalpy b. entropy c. internal energy d. latent heat
Last Answer : enthalpy
Description : The sum of internal energy (U) and the product of pressure and volume (p.v) is known as A. workdone B. entropy C. enthalpy D. none of these
Last Answer : Answer: C
Description : Total heat of a substance is also known as (a) internal energy (b) entropy (c) thermal capacity (d) enthalpy (e) thermal conductance.
Description : __________ decreases during adiabatic throttling of a perfect gas. (A) Entropy (B) Temperature (C) Enthalpy (D) Pressure
Last Answer : (D) Pressure
Description : Vertical lines on pressure-enthalpy chart show constant (a) pressure lines (b) temperature lines (c) total heat lines (d) entropy lines
Last Answer : Ans: c
Description : On the pressure-enthalpy diagram, condensation and de-superheating is represented by a horizontal line because theprocess (a) takes place at constant pressure (b) takes place at constant temperature (c) takes place at constant entropy (d) takes place at constant enthalpy
Last Answer : Ans: a
Description : Short horizontal lines on pressure-enthalpy chart show (a) constant pressure lines (b) constant temperature lines (c) constant total heat lines (d) constant entropy lines
Description : Change in enthalpy of a system is the heat supplied at (a) constant pressure (b) constant temperature (c) constant volume (d) constant entropy (e) N.T.P. condition.
Description : If value of n is infinitely large in a polytropic process pV” = C, then the process is known as constant (a) volume (b) pressure (c) temperature (d) enthalpy (e) entropy
Description : Which of the following parameters is constant for a mole for most of the gases at a given temperature and pressure (a) enthalpy (b) volume (c) mass (d) entropy (e) specific volume.
Last Answer : Answer : b
Description : What is the energy absorbed during chemical reaction under constant volume conditions? A. Entropy B. Ion exchange C. Enthalpy D. Enthalpy of reaction
Last Answer : Enthalpy
Description : Entropy of a substance remains constant during a/an __________ change. (A) Reversible isothermal (B) Irreversible isothermal (C) Reversible adiabatic (D) None of these
Last Answer : (C) Reversible adiabatic
Description : Superheating of steam is done at constant (A) Enthalpy (B) Entropy (C) Pressure (D) Volume
Last Answer : Option C
Description : In Joule-Thomson porous plug experiment, the (A) Enthalpy does not remain constant (B) Entire apparatus is exposed to surroundings (C) Temperature remains constant (D) None of these
Last Answer : (D) None of these
Description : Mollier chart is a __________ plot. (A) Pressure vs. enthalpy (B) Pressure vs. volume (C) Enthalpy vs. entropy (D) Temperature vs. entropy
Last Answer : (C) Enthalpy vs. entropy
Description : What is considered as the heat content of a system? A. Enthalpy B. Entropy C. Internal heat D. Molar heat
Description : An ideal gas is compressed in a cylinder so well insulated that there is essentially no heat transfer. The temperature of gas a. Remains constant b. increases c. decreases d. is basically zero
Last Answer : increases
Description : The entropy __________ in an irreversible cyclic process. A. remains constant B. decreases C. increases
Description : Change in internal energy in a closed system is equal to heat transferred if the reversible process takes place at constant (a) pressure (b) temperature (c) volume (d) internal energy (e) entropy.
Last Answer : Answer : c
Description : In any chemical reaction, a quantity that decrease to a minimum is: w) free energy x) entropy y) temperature z) enthalpy
Last Answer : ANSWER: W -- FREE ENERGY
Description : A closed system is cooled reversibly from 100°C to 50°C. If no work is done on the system (A) its internal energy (U) decreases and its entropy (S) increases (B) U and S both decreases (C) U decreases but S is constant (D) U is constant but S decreases
Last Answer : (B) U and S both decreases
Description : The extensive properties are (A) Volume, mass and number of moles (B) Free energy, entropy and enthalpy (C) Both (A) and (B) (D) None of these
Last Answer : (C) Both (A) and (B)
Description : Pick out the correct statement: (A) In an isothermal system, irreversible work is more than reversible work (B) Under reversible conditions, the adiabatic work is less than isothermal work (C) ... state functions' (D) Matter and energy cannot be exchanged with the surroundings in a closed system
Last Answer : (B) Under reversible conditions, the adiabatic work is less than isothermal work
Description : Pick out the correct statement. (A) Entropy and enthalpy are path functions (B) In a closed system, the energy can be exchanged with the surrounding, while matter cannot be exchanged (C) All the natural processes are reversible in nature (D) Work is a state function
Last Answer : (C) All the natural processes are reversible in nature
Description : Which of the following statements is TRUE about an ELASTIC collision between two particles? Is it true that: w) neither particle loses any of its kinetic energy x) neither particle loses any of ... that lost by the other z) the total kinetic energy before and after the collision remains constant
Last Answer : ANSWER: Z -- THE TOTAL KINETIC ENERGY BEFORE AND AFTER THE COLLISION RE
Description : The heat content of air is called the _____ of the air. a. Temperature b. Humidity c. Enthalpy d. Psychrometry e. Entropy
Last Answer : ANSWER : C
Description : For a thermodynamic system undergoing a process, which of the following pairs best expresses the relationship similar to that expressed by the pressure volume plot? (A) Temperature - entropy (B) Temperature - pressure (C) Enthalpy - entropy
Last Answer : (A) Temperature - entropy
Description : The change in __________ is equal to the reversible work for compression in steady state flow process under isothermal condition. (A) Internal energy (B) Enthalpy (C) Gibbs free energy (D) Helmholtz free energy
Last Answer : (C) Gibbs free energy