Description : Pick out the wrong statement. (A) The net change in entropy in any reversible cycle is always zero (B) The entropy of the system as a whole in an irreversible process increases (C) The ... to a maximum (D) The entropy of a substance does not remain constant during a reversible adiabatic change
Last Answer : (D) The entropy of a substance does not remain constant during a reversible adiabatic change
Description : Assertion :- Entropy of system increases for a spontaneous reactions. Reason :- Enthalpy of reaction always decreases for spontaneous reaction.
Last Answer : Assertion :- Entropy of system increases for a spontaneous reactions. Reason :- Enthalpy of reaction ... D. If both Assertion & Reason are false.
Description : Pick out the correct statement. (A) The available energy in an isolated system for all irreversible (real) processes decreases (B) The efficiency of a Carnot engine increases, if the sink temperature is decreased ... condition is the change in Helmholtz free energy (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : Assertion :- When a rubber band is stretched entropy increases. Reason :- During expansion entropy increases.
Last Answer : Assertion :- When a rubber band is stretched entropy increases. Reason :- During expansion entropy ... D. If both Assertion & Reason are false.
Description : Assertion :- `Q_("Surr")` is zero for adiabatic process Reason :- Final state of the system remains unchanged in adiabatic process.
Last Answer : Assertion :- `Q_("Surr")` is zero for adiabatic process Reason :- Final state of the system ... False. D. If both Assertion & Reason are false.
Description : If a system after undergoing a series of processes, returns to the initial state then (a) process is thermodynamically in equilibrium (b) process is executed in closed system cycle (c) its entropy will ... sum of heat and work transfer will be zero (e) no work will be done by the system.
Last Answer : Answer : d
Description : Entropy change for an adiabatic reversible process is
Last Answer : Entropy change for an adiabatic reversible process is A. Positive B. Zero C. Negative D. Constant
Description : Why entropy change for a reversible adiabatic process is zero ?
Last Answer : Because there is no heat transfer in this process.
Description : Entropy change in case of reversible adiabatic process is (A) Minimum (B) Zero (C) Maximum (D) Indeterminate
Last Answer : (B) Zero
Description : Pick out the wrong statement: (A) The expansion of a gas in vacuum is an irreversible process (B) An isometric process is a constant pressure process (C) Entropy change for a reversible adiabatic process is zero (D) Free energy change for a spontaneous process is negative
Last Answer : (B) An isometric process is a constant pressure process
Description : A thermodynamic process in which entropy is conserved a. isentropic b. adiabatic c. isothermal d. polytropic
Last Answer : isentropic
Description : During the adiabatic process, which of the following is the change in entropy? a. zero b. greater than zero c. less than zero d. infinity
Last Answer : zero
Description : During adiabatic, internally reversible process, what is true about the change in entropy? A. It is temperature-dependent B. It is always greater than zero C. It is always zero D. It is always less than zero
Last Answer : It is always zero
Description : For reversible adiabatic process, change in entropy is (a) maximum (b) minimum (c) zero (d) unpredictable (e) negative
Last Answer : Answer : c
Description : Assertion :- For an isolated system q is zero. Reason :- In an isolated system change in U and V is zero.
Last Answer : Assertion :- For an isolated system q is zero. Reason :- In an isolated system change in U and V ... False. D. If both Assertion & Reason are false.
Description : Assertion :- Entropy is always constant for a closed system. Reason :- Closed system is always reversible.
Last Answer : Assertion :- Entropy is always constant for a closed system. Reason :- Closed system is always ... D. If both Assertion & Reason are false.
Description : Assertion (A): Learning is a life long process. Reason (R): Learning to be useful must be linked with life processes. Choose the correct Answer from the following code (A) Both (A) and (R) are true and (R) is the correct ... (C) (A) is true, but (R) is false (D) (A) is false, but (R) is true.
Last Answer : Answer: 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 : A system undergoes a change from a given initial state to a given final state either by an irreversible process or by a reversible process, then (where, Δ S1 and Δ SR are the entropy changes of the system for the ... S1is sometimes > Δ SR (C) Δ S1is always > Δ SR (D) Δ S1is always = Δ SR
Last Answer : (C) Δ S1is always > Δ SR
Description : Assertion :- Water in liquid state is more stable than ice at room temperature. Reason :- Water in liquid from has higher entropy than ice.
Last Answer : Assertion :- Water in liquid state is more stable than ice at room temperature. Reason :- Water in ... . D. If both Assertion & Reason are false.
Description : Assertion (A): May endothermic reactions that are not spontaneous at room temperature become spontaneous at high temperature. Reason (R ) : Entropy of
Last Answer : Assertion (A): May endothermic reactions that are not spontaneous at room temperature become spontaneous ... . If both Assertion & Reason are false.
Description : Assertion: The enthalpy of formation of gaseous oxygen molecules at `298K` and under1 atm is zero. Reason: The entropy of formation of gaseous oxygen
Last Answer : Assertion: The enthalpy of formation of gaseous oxygen molecules at `298K` and under1 atm is zero. ... D. If both Assertion & Reason are false.
Description : Assertion (A): Enthalpy of graphite is lower than that of diamond. Reason (R ) : Entropy of graphite is lower than that of diamond.
Last Answer : Assertion (A): Enthalpy of graphite is lower than that of diamond. Reason (R ) : Entropy of ... False. D. If both Assertion & Reason are false.
Description : Two ideal gases under same pressure and temperature are allowed to mix in an isolated system. What will be the sign of entropy change?
Last Answer : Ans. Entropy change (∆S) is positive. It is because disorder or degree of freedom increases on mixing.
Description : Entropy change for an irreversible isolated system is (A) ∞ (B) 0 (C) < 0 (D) > 0
Last Answer : (D) > 0
Description : For spontaneous changes in an isolated system (S = entropy) (A) ds = 0 (B) ds 0 (D) ds = Constant
Last Answer : (C) ds > 0
Description : The expression for the work done for a reversible polytropic process can be used to obtain the expression for work done for all processes, except reversible __________ process. (A) Isobaric (B) Isothermal (C) Adiabatic (D) None of these
Last Answer : (B) Isothermal
Description : Which of the following non-flow reversible compression processes require maximum work? (A) Adiabatic process (B) Isothermal process (C) Isobaric process (D) All require same work
Last Answer : (A) Adiabatic process
Description : Which of the following processes is irreversible process (a) isothermal (b) adiabatic (c) throttling (d) all of the above (e) none of the above.
Description : __________ decreases during adiabatic throttling of a perfect gas. (A) Entropy (B) Temperature (C) Enthalpy (D) Pressure
Last Answer : (D) Pressure
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 : A ______ is a flow in which the gas flow is adiabatic and frictionless and entropy change is zero. A. Isentropic flow B. Isobaric flow C. Steady flow D. Uniform flow
Last Answer : Isentropic flow
Description : The processes occuring in open system which permit the transfer of mass to and from the system, are known as A.flow processes B.non-flow processes C.adiabatic processes D.none of these
Last Answer : Answer: A
Description : Assertion : Dark reactions of photosynthesis are temperauture -controlled processes. Reason : Most of the reactions are enzymatic in nature.
Last Answer : Assertion : Dark reactions of photosynthesis are temperauture -controlled processes. Reason : Most of the ... If both Assertion and Reason are false.
Description : Assertion: Some orgainsms can maintain internal homeostasis by means of physiological processes and are called "regulates." Reason: Regulates can main
Last Answer : Assertion: Some orgainsms can maintain internal homeostasis by means of physiological processes and are called " ... Reason are false, then mark (4).
Description : In case of an __________ process, the temperature of the system increases. (A) Isothermal compression (B) Isothermal expansion (C) Adiabatic expansion (D) Adiabatic compression
Last Answer : (D) Adiabatic compression
Description : When a system is in equilibrium for all possible processes, the differential or finite change of entropy is (A) < 0 (B) > 0 (C) = 0 (D) None of these
Last Answer : (A) < 0
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 : It is a common observation that naturally occurring processes have a particular direction associated with them. For instance, heat flows from a hot body to a colder body. The property of a system ... this natural direction of events is called w) energy x) entropy y) enthalpy z) equilibrium
Last Answer : ANSWER: X -- ENTROPY
Description : Consider the following processes: [IES-1999] 1. Constant pressure heat addition. 2. Adiabatic compression. 3. Adiabatic expansion. 4. Constant pressure heat rejection. The correct sequence of these processes in Rankine cycle is: (a) 1, 2, 3, 4 (b) 2, 1, 4, 3 (c) 2, 1, 3, 4 (d) 1, 2, 4, 3
Last Answer : (c) 2, 1, 3, 4
Description : Work done may be calculated by the expression ∫ p dA for __________ processes. (A) Non-flow reversible (B) Adiabatic (C) Both (A) and (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) and (B)
Description : The Carnot cycle is composed of ______ processes. A. One isothermal and one adiabatic B. One isothermal and two adiabatic C. Two isothermal and one adiabatic D. Two isothermal and two adiabatic
Last Answer : Two isothermal and two adiabatic
Description : Which of the following processes are thermodynamically reversible (a) throttling (b) free expansion (c) constant volume and constant pressure (d) hyperbolic and pV = C (e) isothermal and adiabatic.
Last Answer : Answer : e
Description : The total entropy change for a system and its surroundings increases, if the process is
Last Answer : The total entropy change for a system and its surroundings increases, if the process is A. Reversible B. Irreversible C. Exothermic D. Endothermic
Description : The air standard Otto cycle comprises a two constant pressure processes and two constant volume processes b two constant pressure and two constant entropy processes c. two constant volume processes and two constant entropy processes d. none of the above.
Last Answer : ANSWER (c) two constant volume processes and two constant entropy processes
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 : (i)State why heat changes in physical and chemical processes are indicated by enthalpy changes and not by entropy changes? (ii)What are the limitations of First Law of thermodynamics?
Last Answer : (i) Most of the processes are carried out in an open system i.e, at constant pressure. (ii)(a) Can’t explain the feasibility of the reaction. (b)It poses no restriction on the direction of flow of heat. (c)Practically it is not possible to convert the heat energy into an equivalent amount of work.
Description : _________ does not change during phase transformation processes like sublimation, melting & vaporisation. (A) Entropy (B) Gibbs free energy (C) Internal energy (D) All (A), (B) & (C)
Last Answer : (B) Gibbs free energy
Description : When ice cubes are made, the entropy of water – (1) does not change (2) decreases (3) increases (4) may either increase or decrease depending on the process used
Last Answer : (2) decreases Explanation: When water is frozen into ice, the temperature drops below 0°C. Since the entropy of the solid is less than that of the liquid, the entropy of the water (the system ... decrease is found by dividing the heat of fusion of ice by the temperature for the reversible pathway.
Description : For a spontaneous process, free energy (A) Is zero (B) Increases (C) Decreases whereas the entropy increases (D) And entropy both decrease
Last Answer : C) Decreases whereas the entropy increases