6-Thermodynamics-with-answers.pdf

THERMODYNAMICS - INDIABIX SECTION 1 b. first 1. Maximum work that could be secured by expanding c. second the gas over a given pressure range is the d. third __________ w...

THERMODYNAMICS - INDIABIX SECTION 1 b. first 1. Maximum work that could be secured by expanding c. second the gas over a given pressure range is the d. third __________ work. a. isothermal 10. For a spontaneous process, free energy b. adiabatic a. is zero c. isentropic b. increases d. none of these c. decreases whereas the entropy increases d. and entropy both decrease 2. Internal energy change of a system over one complete cycle in a cyclic process is 11. A refrigeration cycle is a reversed heat engine. a. zero Which of the following has the maximum value of the b. +ve co-efficient of performance (COP) for a given c. -ve refrigeration effect ? d. dependent on the path a. Vapor compression cycle using expansion valve. 3. Heating of water under atmospheric pressure is an b. Air refrigeration cycle. __________ process. c. Vapor compression cycle using expansion a. isochoric engine. b. isobaric d. Carnot refrigeration cycle. c. adiabatic d. isothermal 12. In a working refrigerator, the value of COP is always 4. Van Laar equation deals with the activity co- a. 0 efficients in b. < 0 a. binary solutions c. < 1 b. ternary solutions d. >1 c. azeotropic mixture only d. none of these 13. __________ increases with increase in pressure. a. The melting point of wax 5. High __________ is an undesirable property for a b. The boiling point of a liquid good refrigerant. c. both (a) and (b) a. specific heat d. neither (a) nor (b) b. latent heat of vaporisation c. viscosity 14. A refrigerator may be termed as a d. specific vapor volume a. heat pump b. heat engine 6. Solubility of a substance which dissolves with an c. Carnot engine increase in volume and liberation of heat will be d. none of these favoured by the a. low pressure and high temperature. 15. For a stable phase at constant pressure and b. low pressure and low temperature. temperature, the fugacity of each component in a c. high pressure and low temperature. binary system __________ as its mole fraction d. high pressure and high temperature. increases. a. decreases 7. Entropy is a measure of the __________ of a b. increases system. c. remains same a. disorder d. decreases linearly b. orderly behaviour c. temperature changes only 16. Which of the following is not an intensive property d. none of these ? a. Chemical potential 8. A chemical reaction will occur spontaneously at b. Surface tension constant pressure and temperature, if the free energy c. Heat capacity is d. None of these a. zero b. positive 17. Out of the following refrigration cycles, which one c. negative has the minimum COP (Co-efficient of performance)? d. none of these a. Air cycle b. Carnot cycle 9. Fundamental principle of refrigeration is based on c. Ordinary vapour compression cycle the __________ law of thermodynamics. d. Vapour compression with a reversible a. zeroth expansion engine  THERMODYNAMICS - INDIABIX 18. Measurement of thermodynamic property of 26. "At the absolute zero temperature, the entropy of temperature is facilitated by __________ law of every perfectly crystalline substance becomes zero". thermodynamics. This follows from the a. 1st a. third law of thermodynamics b. zeroth b. second law of thermodynamics c. 3rd c. Nernst heat theorem d. none of these d. Maxwell's relations 19. The theoretical minimum work required to separate 27. During Joule-Thomson expansion of gases (Page one mole of a liquid mixture at 1 atm, containing 50 2-182) mole % each of n- heptane and n- octane into pure a. enthalpy remains constant. compounds each at 1 atm is b. entropy remains constant. a. -2 RT ln 0.5 c. temperature remains constant. b. -RT ln 0.5 d. none of these. c. 0.5 RT d. 2 RT 28. The accentric factor of a materical, 'ω', is defined as ω = -log10(Prsat)Tr-1 = 0.7, where, Prsat = reduced 20. Keeping the pressure constant, to double the vapor pressure, Tr = reduced temperature. The value volume of a given mass of an ideal gas at 27°C, the of accentric factor is always temperature should be raised to __________ °C. a. 2 a. 270 b. < 1 b. 327 c. 1 c. 300 d. < 3 d. 540 29. Degress of freedom at triple point will be (E4-129) 21. Entropy of an ideal gas depends upon its a. 0 a. pressure b. 1 b. temperature c. 2 c. both (a) & (b) d. 3 d. neither (a) nor (b) 30. “Law of corresponding states" says that 22. Isobaric process means a constant process. a. two different gases behave similarly, if their a. temperature reduced properties (i.e. P, V and T) are b. pressure same. c. volume b. the surface of separation (i. e. the meniscus) d. entropy between liquid and vapour phase disappears at the critical temperature. 23. No work is done by the system, when a reaction c. no gas can be liquified above the critical occurs at constant temperature, howsoever high the pressure a. volume may be. b. temperature d. the molar heat of energy of gas at constant c. pressure volume should be nearly constant (about 3 d. none of these calories). 24. If the vapour pressure at two temperatures of a 31. Linde gas liquefaction process employs cooling solid phase in equilibrium with its liquid phase are a. by throttling known, then the latent heat of fusion can be calculated b. by expansion in an engine by the c. at constant pressure a. Maxwell's equation d. none of these b. Clayperon-Claussius equation c. Van Laar equation d. Nernst Heat Theorem 32. Pick out the wrong statement pertaining to the decomposition of PCl5 represented by, 25. The freezing point of a liquid decreases when the PCl5 PCl3 + Cl2.Degree of dissociation of pressure is increased, if the liquid __________ while freezing. PCl5 will a. contracts a. decrease on addition of Cl2. b. expands b. increase on addition of an inert gas at constant c. does not change in volume pressure. d. either (a), (b) or (c) c. decrease on increasing the pressure of the system. d. none of these  THERMODYNAMICS - INDIABIX 33. Joule-Thomson experiment is 40. Which of the following is a thermodynamic property a. isobaric of a system ? b. adiabatic a. Concentration c. isenthalpic b. Mass d. both(b) & (c) c. Temperature d. Entropy 34. Boyle's law for gases states that 41. Equilibrium constant decreases as the temperature a. increases, for an exothermic reaction. a. , when temperature is constant. b. decreases, for an exothermic reaction. c. increases, for an endothermic reaction. b. , when temperature & mass of the d. none of these. gas remain constant. c. P ∝ V, at constant temperature & mass of the 42. The expression, , gives the gas. free energy change d. = constant, for any gas. a. with pressure changes at constant temperature. b. under reversible isothermal volume change. 35. 1st law of thermodynamics is nothing but the law of c. during heating of an ideal gas. conservation of d. during cooling of an ideal gas. a. momentum b. mass 43. All gases during throttling process at atmospheric c. energy temperature and pressure show a cooling effect except d. none of these a. CO2 b. H2 36. In a reversible chemical reaction (where, Δx = c. O2 number of moles of products-number of moles of d. N2 reactants ) a. addition of inert gas favours the forward 44. Compressibility factor for almost all the gases are reaction, when Δx is positive. approximately same at the same b. pressure has no effect on equilibrium, when a. pressure and temperature. Δn = 0. b. reduced pressure and reduced c. addition of inert gas has no effect on the temperature. equilibrium constant at constant volume for c. critical pressure and critical temperature. any value of Δx (+ ve, - ve) or zero). d. none of these. d. all 'a', 'b' & 'c'. 45. Pick out the wrong statement. 37. Out of the following refrigeration cycles, which one a. Activity co-efficient is dimensionless. has maximum COP ? b. In case of an ideal gas, the fagacity is equal to a. Air cycle its pressure. b. Carnot cycle c. In a mixture of ideal gases, the fugacity of a c. Ordinary vapor compression cycle component is equal to the partial pressure of d. Vapor compression with a reversible the component. expansion engine d. The fugacity co-efficient is zero for an ideal gas. 38. Pick out the correct statement: a. In an isothermal system, irreversible work is 46. The co-efficient of performance (COP) of a more than reversible work. refrigerating system, which is its index of performance, b. Under reversible conditions, the adiabatic is defined as the ratio of useful refrigeration to the net work is less than isothermal work. work. The units of __________ and COP are the c. Heat, work, enthalpy and entropy are all 'state same. functions'. a. kinematic viscosity d. Matter and energy can not be exchanged with b. work the surroundings in a closed system. c. temperature d. none of these 39. In any spontaneous process, a. only F decreases 47. The chemical potential of a component (μi) of a b. only A decreases phase is the amount by which its capacity for doing all c. both F and A decreases work, barring work of expansion is increased per unit d. both F and A increase amount of 3ubstance added for an infinitesimal  THERMODYNAMICS - INDIABIX addition at constant temperature and pressure. It is given by 4. Heat pump a. accomplishes only space heating in winter. b. accomplishes only space cooling in summer. c. accomplishes both (a) and (b). a. d. works on Carnot cycle. 5. The temperature at which both liquid and gas b. phases are identical, is called the __________ point. a. critical b. triple c. c. freezing d. all (a), (b) and (c) d. boiling 6. What is the value of ln y (where y = activity co- 48. In jet refrigerators, the refrigerating fluid is efficient) for ideal gases ? practically always a. Zero a. water b. Unity b. ammonia c. Infinity c. freon d. Negative d. brine 7. A closed system is cooled reversibly from 100°C to 50°C. If no work is done on the system 49. Water on heating from 1 to 4°C a. its internal energy (U) decreases and its a. contracts entropy (S) increases. b. expands b. U and S both decreases c. has same volume c. U decreases but S is constant. d. may contract or expand d. U is constant but S decreases. 8. Which is not a refrigerant ? 50. Pick out the correct statement. a. SO2 a. Compression ratio of an Otto engine is b. NH3 comparatively higher than a diesel engine. c. CCl2F2 b. Efficiency of an Otto engine is higher than d. C2H4Cl2 that of a diesel engine for the same compression ratio. 9. The partial pressure of each constituent present in c. Otto engine efficiency decreases with the rise an alloy is __________ the total vapor pressure in compression ratio, due to decrease in work exerted by the alloy. produced per quantity of heat. a. less than d. Diesel engine normally operates at lower b. equal to compression ratio than an Otto engine for an c. more than equal output of work. d. either (b) or (c); depends on the type of alloy SECTION 2 10. Heat is added at constant pressure in an ideal 1. When pressure is applied on the system, ice __________ cycle. water, then a. Stirling a. equilibrium can not be established. b. Brayton b. more ice will be formed. c. Rankine c. more water will be formed. d. both (b) and (c) d. evaporation of water will take place. 11. Entropy change of mixing two liquid substances 2. Partial molar free energy of an element A in solution depends upon the is same as its a. molar concentration a. chemical potential b. quantity (i.e. number of moles) b. activity c. both (a) and (b) c. fugacity d. neither (a) nor (b) d. activity co-efficient 12. The four properties of a system viz. P, V, T, S are 3. Free energy change at equilibrium is related by __________ equation. a. zero a. Gibbs-Duhem b. positive b. Gibbs-Helmholtz c. negative c. Maxwell's d. indeterminate d. none of these  THERMODYNAMICS - INDIABIX b. Melting point of wax 13. If the pressure on 100 c.c. of air is halved, then its c. Boiling point of liquids volume (at the same temperature) would be d. none of these __________ c.c. a. 100 20. Isentropic process means a constant __________ b. 50 process. c. 205 a. enthalpy d. 200 b. pressure c. entropy. 14. Pick out the wrong statement. d. none of these a. Cp of monoatomic gases such as metallic vapor is about 5 kcal/kg.atom. 21. is the mathematical expression b. The heat capacity of solid inorganic substance is exactly equal to the heat capacity of the substance in the molten a. Joule-Thomson co-efficient. state. b. specific heat at constant pressure (Cp). c. There is an increase in entropy, when a c. co-efficient of thermal expansion. spontaneous change occurs in an isolated d. specific heat at constant volume (CV). system. d. At absolute zero temperature, the heat 22. In case of steady flow compression polytropic capacity for many pure crystalline substances process (PVn = constant), the work done on air is the is zero. lowest, when a. n = y = 1.4 15. The principle applied in liquefaction of gases is b. n = 0 a. adiabatic expansion. c. n = 1 b. Joule-Thomson effect. d. n = 1.66 c. both (a) and (b). d. neither (a) nor (b). 23. A liquid under pressure greater than its vapour pressure for the temperature involved is called a 16. Co-efficient of performance for a reversed Carnot __________ liquid. cycle working between a. subcooled temperatures T1 and T2 (T1 > T2) is b. saturated c. non-solidifiable d. none of these a. 24. For a real gas, the chemical potential is given by a. RT dlnP b. b. RT dlnf c. R dlnf d. none of these c. 25. At absolute zero temperature, all substances have the same d. a. heat capacity b. crystalline structure 17. The number of degrees of freedom for an c. entropy azeotropic mixture in a two component vapour-liquid d. none of these equilibria is/are a. zero 26. Lowering of condenser temperature (keeping the b. one evaporator temperature constant) in case of vapour c. two compression refrigeration system results in d. three a. increased COP. b. same COP. 18. Any substance above its critical temperature exists c. decreased COP. as d. increased or decreased COP ; depending a. saturated vapour upon the type of refrigerant b. solid c. gas 27. Pick out the correct statement. d. liquid a. If an insoluble gas is passed through a volatile liquid placed in a perfectly insulated container, 19. Which of the following decreases with increase in the temperature of the liquid will increase. pressure ? b. A process is irreversible as long as Δ S for the a. Melting point of ice system is greater than zero.  THERMODYNAMICS - INDIABIX c. The mechanical work done by a system is always equal to P.dV. d. The heat of formation of a compound is defined as the heat of reaction leading to the formation of the compound from its reactants. 28. Grams of butane (C4H10) formed by the liquefaction a. of 448 litres of the gas (measured at (STP) would be a. 580 b. 640 c. 1160 d. data insufficient; can't be computed 29. The thermodynamic law, PVy = constant, is not applicable in case of a. ideal compression of air. b. b. free expansion of an ideal gas. c. adiabatic expansion of steam in a turbine. d. adiabatic compression of a perfect gas. 30. What is the value of maximum COP in case of absorption refrigeration, if refrigeration provided is at temperature, TR(where, T1 and T2 are source & surrounding temperatures respectively.)? c. a. 35. Specific heat of a gas for a reversible adiabatic process is b. a. negative b. zero c. infinity d. none of these c. d. none of these 36. When a gas in a vessel expands, its internal 31. Mollier diagram is a plot of energy decreases. The process involved is a. temperature vs. enthalpy a. reversible b. temperature vs. enthalpy b. irreversible c. entropy vs. enthalpy c. isothermal d. temperature vs. internal energy d. adiabatic 32. is the mathematical expression for 37. A system is said to be isopiestic, if there is no __________ change. a. temperature b. pressure a. CV c. volume b. enthalpy change d. none of these c. free energy change d. none of these 38. In a turbine, the fluid expands almost a. isothermally 33. The activity of an ideal gas is numerically b. isobarically __________ its pressure. c. adiabatically a. more than d. none of these b. less than c. equal to 39. The unity of Planck's constant 'h' in the d. data insufficient, can't be predicted equation, E = hv is a. J/s 34. Which of the following diagrams does not b. J.S represent an Otto cycle ? c. J/kmol  THERMODYNAMICS - INDIABIX d. kmol/J b. decreases c. remains unchanged 40. Specific/molar Gibbs free energy for a pure d. decreases linearly substance does not change during a. sublimation 47. Co-efficient of Performance (COP) of a refrigerator b. vaporisation is the ratio of the c. melting a. work required to refrigeration obtained. d. either (a), (b) or (c) b. refrigeration obtained to the work required. c. lower to higher temperature. 41. Refrigeration capacity of a household refrigerator d. higher to lower temperature. may be round about __________ tons. a. 0.15 48. The Maxwell relation derived from the differential b. 1.5 expression for the Helmholtz free energy (dA) is c. 4.5 d. 6.5 a. 42. is the mathematical expression for b. a. CV b. entropy change c. Gibbs free energy d. none of these c. 43. An ideal gas is taken around the cycle ABCA as shown in P-V diagram below : d. 49. A solid metallic block weighing 5 kg has an initial temperature of 500°C. 40 kg of water initially at 25°C is contained in a perfectly insulated tank. The metallic block is brought into contact with water. Both of them come to equilibrium. Specific heat of block material is 0.4 kJ.kg-1. K-1. Ignoring the effect of expansion and contraction and also the heat capacity to tank, the total entropy change in kJ.kg-1 , K-1 is a. -1.87 b. 0 c. 1.26 d. 3.91 50. dW and dq are not the exact differential, The work done by the gas during the cycle is equal to because q and Ware a. 12 P1V1 a. state functions b. 6 P1 V1 b. path functions c. 3 P1V1 c. intensive properties d. P1 V1 d. extensive properties 44. Chemical potential is a/an SECTION 3 a. extensive property. 1.Trouton's ratio of __________ liquids is calculated b. intensive property. using Kistyakowsky equation. c. force which drives the chemical system to a. polar equilibrium. b. non-polar d. both (b) and (c). c. both (a) & (b) 45. In polytropic process (PVn = constant), if n = 1; it d. neither (a) nor (b) means a/an __________ process. 2. Activity co-efficient is a measure of the a. adiabatic a. departure from ideal solution behaviour. b. reversible b. departure of gas phase from idea] gas law. c. isothermal c. vapour pressure of liquid. d. none of these d. none of these. 46. The melting point of paraffin wax (which contracts on solidification) __________ with pressure rise. a. increases  THERMODYNAMICS - INDIABIX 3. While dissolving a gas into a liquid at a constant temperature, the ratio of the concentration of the gas in 12. Pick out the wrong statement. the solution phase and in the gaseous phase is a. A closed system does not permit exchange of a. infinity mass with its surroundings but may permit b. unity exchange of energy. c. constant b. An open system permits exchange of both d. negative mass and energy with its surroundings. c. The term microstate is used to characterise an 4. Which of the following units is not present in both individual, whereas macro-state is used to the vapor compression refrigeration system and designate a group of micro-states with absorption refrigeration system ? common characteristics. a. Expansion valve d. none of the above. b. Condenser c. Refrigerator 13. Which of the following exemplifies an adiabatic d. Compressor process ? a. Melting of ice. 5. For an isothermal reversible compression of an ideal b. Condensation of alcohol vapor. gas c. Sudden bursting of a cycle tube. a. only ΔE = 0 d. Evaporation of water. b. only ΔH =0 c. ΔE = ΔH = 0 14. Entropy, which is a measure of the disorder of a d. dQ = dE system is a. independent of pressure. 6. Melting of ice exemplifies a/an b. independent of temperature. a. adiabatic process. c. zero at absolute zero temperature for a b. endothermic reaction. perfect crystalline substance. c. exothermic reaction. d. all (a), (b) & (c) d. process involving a chemical reaction. 15. Critical temperature is defined as the temperature 7. A refrigeration cycle is the same as a __________ above which a gas will cycle, a. not liquify (barring exceptions). a. turbine b. immediately liquify. b. heat engine c. never liquify however high the pressure c. reversed heat engine may be. d. none of these d. none of these. 8. At __________ point, all the three phases (i.e.solid, 16. The standard Gibbs free energy change of a liquid and gas) co-exist. reaction depends on the equilibrium a. eutcetic a. pressure b. triple b. temperature c. plait c. composition d. critical d. all (a), (b) and (c) 9. Kopp's rule is used to calculate the heat capacity of 17. Gibbs-Duhem equation relates composition in a. solids liquid phase and the __________ at constant b. liquids temperature & pressure. c. gases a. fugacity d. all (a), (b) & (c) b. partial pressure c. activity co-efficient 10. __________ explains the equilibrium constant for d. (a), (b), and (c) any chemical reaction. a. Henry's law 18. In an ideal solution, the activity of a component b. Law of mass action equals its c. Hess's law a. mole fraction. d. none of these b. fugacity at the same temperature and pressure. 11. Which of the following is not a reversible process ? c. partial pressure. a. Expansion of an ideal gas against constant d. none of these. pressure. b. Atmospheric pressure vaporisation of water at 19. A gas has a volume of 27.3 c.c. at 0°C. Its volume 100°C. at 10°C (if pressure remains unchanged) will be c. Solution of NaCl in water at 50°C. __________ c.c. d. None of these. a. 2.73  THERMODYNAMICS - INDIABIX b. 28.3 c. The work done by expansion of a gas in c. 273 vacuum is zero. d. 283 d. CP and CV are state function. 20. Clayperon equation deals with the 27. Compressibility factor of a gas is a. rate of change of vapour pressure with a. not a function of its pressure. temperature. b. not a function of its nature. b. effect of an inert gas on vapour pressure. c. not a function of its temperature. c. calculation of ΔF for spontaneous phase d. unity, if it follows PV = nRT. change. d. temperature dependence of heat of phase 28. Which of the following is not an extensive property transition. ? a. Free energy 21. b. Entropy Gibbs free energy (G) is represented by, G= H - TS, c. Refractive index whereas Helmholtz free energy, (A) is given d. None of these by, A =E - TS. Which of the following is the Gibbs- Helmholtz equation 29. Forward reaction will be favoured for the exothermic reaction, represented by CO + H2O CO2 + H2, by a. a. low temperature and high pressure. b. low temperature and low pressure. c. high temperature and high pressure. b. d. high temperature and low pressure. c. both (a) and (b) d. neither (a) nor (b) 30. Enthalpy of a gas depends upon its a. temperature 22. Which of the following is an undesirable b. mass characteristics of a refrigerant ? c. volume a. It should be non-explosive. d. pressure b. It should have a sub-atmospheric vapor pressure at the temperature in refrigerator 31. When dilute aqueous solutions of two salts are coils. mixed, the process is associated with c. Its vapor pressure at the condenser a. decrease in temperature. temperature should be very high. b. increase in temperature. d. None of these. c. no change in temperature. d. change in temperature which is a function of 23. "The rate at which a substance reacts is composition. proportional to its active mass and the rate of a chemical reaction is proportional to the product of 32. Pick out the correct statement. active masses of the reacting substances". This is the a. Like internal energy and enthalphy, the a. Lewis-Randall rule. absolute value of standard entropy for b. statement of Vant-Hoff equation. elementary substances is zero. c. Le-Chatelier's principle. b. Melting of ice involves increase in enthalpy d. none of these. and a decrease in randomness. c. The internal energy of an ideal gas depends 24. What is the ratio of adiabatic compressibility to only on its pressure. isothermal compressibility ? d. Maximum work is done under reversible a. 1 conditions. b. < 1 c. >1 33. Chemical engineering thermodynamics is d. >> 1 concerned with the __________ in/of chemical processes. 25. The absolute entropy for all crystalline substances a. reaction mechanism at absolute zero temperature is b. calculation of rates a. zero c. energy transformation from one form to the b. negative another c. more than zero d. none of these d. indeterminate 34. An isolated system can exchange __________ 26. Pick out the wrong statement. with its surroundings. a. Phase rule variables are intensive properties. a. matter b. Heat and work are both state function.  THERMODYNAMICS - INDIABIX b. energy 41. Pick out the wrong statement. c. neither matter nor energy a. Trouton's ratio of non-polar liquids is d. both matter and energy calculated using Kistyakowasky equation. b. Thermal efficiency of a Carnot engine is 35. Requisites of a reversible process is that the always less than 1. a. system and surroundings pressure be equal. c. An equation relating pressure, volume and b. friction in the system should be absent. temperature of a gas is called ideal gas c. system and surroundings temperature be equation. equal. d. none of these. d. none of these. 42. Which of the following is clausius-Clayperon 36. Fugacity is most helpful in equation for vaporisation of an ideal gas under the a. representing actual behaviour of real condition that the molar volume of liquid is negligible gases. compared to that of the vapor ? b. representing actual behaviour of ideal gases. c. the study of chemical equilibria involving gases at atmospheric pressure. a. d. none of these 37. The energy of activation of exothermic reaction is b. a. zero. b. negative. c. very large compared to that for en-dothermic c. reaction. d. not possible to predict. d. 38. Pick out the wrong statement. a. The chemical potential of a pure substance 43. When a gas is subjected to adiabatic expansion, it depends upon the temperature and pressure. gets cooled due to b. The chemical potential of a component in a a. decrease in velocity. system is directly proportional to the escaping b. decrease in temperature. tendency of that component. c. decrease in kinetic energy. c. The chemical potential of ith species (μi) in d. energy spent in doing work. an ideal gas mixture approaches zero as the pressure or mole fraction (xi) tends to 44. Joule-Thomson effect i.e., a throttling process is a be zero at constant temperature. constant __________ process. d. The chemical potential of species 'i' in the a. entropy mixture (μi) is mathematically represented b. temperature c. internal energy d. enthalpy as, , 45. In the equation, PVn = Constant, if the value of n = where, n, ni and nj respectively denote the total 0, then it represents a reversible __________ process. number of moles, moles of ith species and all a. isobaric mole numbers except ith species. 'G' is Gibbs b. isothermal molar free energy. c. isentropic d. isometric 39. In the reaction; N2 + O2 2NO, increasing the 46. Work done in an adiabatic process between two pressure will result in states depends on the a. shifting the equilibrium towards right, a. rate of heat transmission b. shifting the equilibrium towards left. b. initial state only c. no change in equilibrium condition. c. end states only d. none of these. d. none of these 40. A cyclic engine exchanges heat with two reservoirs 47. The number of degree of freedom for an azeotropic maintained at 100 and 300°C respectively. The mixture of ethanol and water in vapour-liquid maximum work (in J) that can be obtained from 1000 J equilibrium, is of heat extracted from the hot reservoir is a. 3 a. 349 b. 1 b. 651 c. 2 c. 667 d. 0 d. 1000  THERMODYNAMICS - INDIABIX 48. The internal energy of an ideal gas is a function of d. half its __________ only. a. molecular size 7. The free energy change for a chemical reaction is b. volume given by (where, K = equilibrium constant) c. pressure a. RT lnK d. temperature b. -RT lnK c. -R lnK 49. At constant temperature and pressure, for one d. T lnK mole of a pure substance, the ratio of the free energy to the chemical potential is 8. Free energy, fugacity and activity co-efficient are all a. zero affected by change in the temperature. The fugacity b. one co-efficient of a gas at constant pressure ____with the c. infinity increase of reduced temperature. d. negative a. decreases b. increases 50. The change in __________ is equal to the c. remains constant reversible work for compression in steady state flow d. decreases logarithmically process under isothermal condition. a. internal energy b. enthalpy 9. In the reaction, H2 +I2 2HI, addition of an inert c. Gibbs free energy gas will d. Helmholtz free energy a. increase the partial pressure of H2. b. increase the partial pressure of I2. SECTION 4 c. increase the total pressure and hence shift the 1. Work done is a equilibrium towards the right. a. property of the system d. not effect the equilibrium conditions b. path function c. point function 10. What is the number of degrees of freedom for d. state description of a system liquid water in equilibrium with a mixture of nitrogen and water vapor ? 2. Entropy of the system decreases, when a. 2 a. snow melts into water. b. 0 b. a gas expands spontaneously from high c. 3 pressure to low pressure. d. 1 c. water is converted into ice. d. both (b) & (c). 11. The temperature at which a real gas obeys the ideal gas laws over a wide range of pressure is called 3. Extensive properties of a thermodynamic system the __________ temperature. depend upon the __________ of the system. a. critical a. specific volume b. Boyle b. temperature c. inversion c. mass d. reduced d. pressure 12. If the molar heat capacities (Cp or Cv) of the 4. The equation Tds = dE - PdV applies to reactants and products of a chemical reaction are a. single phase fluid of varying composition. identical, then, with the increase in temperature, the b. single phase fluid of constant composition. heat of reaction will c. open as well as closed systems. a. increase d. both (b) and (c) b. decrease c. remain unaltered 5. If an ideal solution is formed by mixing two pure d. increase or decrease ; depends on the liquids in any proportion, then the __________ of particular reaction mixing is zero. a. enthalpy 13. All gases above its inversion temperature, in a b. volume throttling process will show c. both 'a' & 'b' a. a heating effect. d. neither 'a' nor 'b' b. no change in temperature. c. a cooling effect. 6. Near their critical temperatures, all gases occupy d. either (a) or (c). volumes __________ that of the ideal gas. a. less than 14. First law of thermodynamics is mathematically b. same as stated as c. more than a. dQ = dE + dW  THERMODYNAMICS - INDIABIX b. dQ = dE - dW 22. __________ law of thermodynamics ascertains the c. dE = dQ + dW direction of a particular spontaneous process. d. dW = dQ + dE a. Zeroth b. First 15. Pick out the wrong statement. c. Second a. Surface tension of a substance vanishes at d. Third critical point, as there is no distinction between liquid and vapour phases at its critical point. 23. At normal boiling point, molar entropy of b. Entropy of a system decreases with the vaporisation is __________ Joule/K°.mole. evolution of heat. a. 72 c. Change of internal energy is negative for b. 92 exothermic reactions. c. 142 d. The accentric factor for all materials is d. 192 always more than one. 24. For an ideal solution, the value of activity co- 16. Translational kinetic energy of molecules of an efficient is ideal gas is proportional to (where, T = absolute a. 0 temperature of the gas ) b. 1 a. T c. < 1 b. Srqt root of T d. >1 c. T2 d. 1/ (sqrt root of T) 25. The expression, nCv(T2 - T1), is for the __________ of an ideal gas. 17. Equation which relates pressure, volume and a. work done under adiabatic condition temperature of a gas is called the b. co-efficient of thermal expansion a. equation of state c. compressibility b. Gibbs Duhem equation d. none of these c. ideal gas equation d. none of these 26. The number of degrees of freedom at the triple point of water is 18. Claussius-Clayperon equation gives accurate a. 0 result, when the b. 1 a. vapour pressure is relatively low and the c. 2 temperature does not vary over wide limits. d. 3 b. vapour obeys the ideal gas law and the latent heat of vaporisation is constant. 27. Which of the following is a widely used refrigerant c. volume in the liquid state is negligible in vapour compression refrigeration system (using compared with that in the vapour state. large centrifugal compressor)? d. all (a), (b) and (c). a. Freon b. Liquid sulphur dioxide 19. The temperature at which a real gas obeys the c. Methyl chloride ideal gas laws over a wide range of pressure is called d. Ammonia __________ temperature. a. Boyle 28. Internal energy is equal to the heat absorbed in b. inversion case of a/an __________ process. c. critical a. constant volume d. reduced b. polytropic c. adiabatic 20. The expression for entropy change, ΔS = n Cp. ln d. constant pressure (T2/T1), is valid for the __________ of a substance. a. simultaneous pressure & temperature change 29. The first law of thermodynamics is a restatement of b. heating the law of conservation of c. cooling a. mass d. both (b) and (c) b. energy c. momentum 21. For a single component two phase mixture, the d. none of these number of independent variable properties are a. two 30. Joule-Thomson co-efficient for a perfect gas is b. one a. zero c. zero b. positive d. three c. negative d. none of these  THERMODYNAMICS - INDIABIX 31. In an adiabatic process, the b. ideal solutions a. heat transfer is zero. c. non-ideal mixtures b. temperature change is zero. d. a pure component c. work done is a path function. d. enthalpy remains constant. 40. Number of degrees of freedom for a three phase system in equilibrium comprising of three non-reacting 32. A nozzle is a device, which chemical species is a. increases kinetic energy and decreases a. 2 pressure. b. 0 b. reduces kinetic energy and increases c. 1 pressure. d. 3 c. reduces both kinetic energy and pressure. d. increases both kinetic energy and pressure. 41. Critical solution temperature (or the con-solute temperature) for partially miscible liquids (e.g., phenol- 33. During the phase transition, __________ changes. water) is the minimum temperature at which a. pressure a. a homogeneous solution (say of phenol b. volume water) is formed. c. temperature b. mutual solubility of the two liquids shows a d. all (a), (b) and (c) decreasing trend. c. two liquids are completely separated into two 34. The work done in an adiabatic change in a layers. particular gas depends upon changes in the d. none of these. __________ only. a. temperature 42. Which is not constant for an ideal gas ? b. specific heat c. volume d. pressure a. 35. The value of gas constant 'R' is a. 1.987 cal/gm mole °K b. 1.987 BTU/lb. mole °R b. c. both (a) and (b) d. neither (a) nor (b) c. 36. In an isothermal process on an ideal gas, the d. all (a), (b) & (c) pressure increases by 0.5 percent. The volume decreases by about __________ percent. 43. Enthalpy 'H' is defined as a. 0.25 a. H = E - PV b. 0.5 b. H = F - TS c. 0.75 c. H - E = PV d. 1 d. none of these 37. Which of the following is not a unit of the 44. One ton of refrigeration is defined as the heat rate equilibrium constant Kp? (where, Δx = number of corresponding to melting of one ton of ice in one moles of products number of moles of reactants) a. hour a. (atm)Δx, when Δx is negative b. day b. (atm)Δx, when Δx is positive c. minute c. Dimensionless, when Δx = 0 d. second d. (atm)Δx2, when Δx > 0 45. __________ functions are exemplified by heat and 38. Pick out the correct statement. work. a. The available energy in an isolated system for a. Path all irreversible (real) processes decreases. b. Point b. The efficiency of a Carnot engine increases, if c. State the sink temperature is decreased. d. none of these c. The reversible work for compression in non- flow process under isothermal condition is the 46. In an irreversible process change in Helmholtz free energy. a. Tds = dE - dW = 0 d. all (a), (b) and (c) b. dE - dW - Tds = 0 c. Tds - dE + dW< 0 39. Partial molal quantities are important in the study d. Tds - dT + dW< 0 of a. ideal gases  THERMODYNAMICS - INDIABIX 47. What is the number of degree of freedom for a c. low pressure & low temperature. system of two miscible non-reacting species in vapor- d. none of these. liquid equilibrium forming an azeotrope ? a. 3 5. Internal energy of an element at 1 atm and 25° C is b. 2 __________ kcal/kg.mole. c. 1 a. 0 d. 0 b. 273 c. 25 48. The entropy change in a reversible isothermal d. none of these process, when an ideal gas expands to four times its initial volume is 6. Which of the following liquid metals has the highest a. R loge 4 thermal conductivity ? b. R log10 4 a. Molten sodium c. Cv log10 4 b. Molten lead d. Cv loge 4 c. Mercury d. Molten potassium 49. PVγ = Constant (where, γ = Cp/Cv) is valid for a/an __________ process. 7. Which of the following has the least thermal a. isothermal efficiency ? b. isentropic a. Steam engine c. isobaric b. Carnot engine d. adiabatic c. Diesel engine d. Otto engine 50. Claude gas liquefaction process employs cooling a. at constant pressure. 8. If the internal energy of an ideal gas decreases by b. by throttling. the same amount as the work done by the system, c. by expansion in an engine. then the d. none of these. a. process must be isobaric. b. temperature must decrease. SECTION 5 c. process must be adiabatic. 1. The heat capacities for the ideal gas state depend d. both (b) and (c). upon the a. pressure 9. Joule-Thomson Co-efficient at any point on the b. temperature inversion curve is c. both (a) & (b) a. ∞ d. neither (a) nor (b) b. + ve c. 0 2. Which of the following will increase the volume of a d. -ve real gas by four times ? a. Doubling the absolute temperature as well as 10. Pick out the wrong statement. pressure of the gas. b. Reducing pressure to one fourth at constant temperature. a. The values of are c. Reducing temperature to one fourth at zero for a real gas at its critical point. constant pressure. b. Heat transferred is equal to the change in the d. Reducing the temperature to half and doubling enthalpy of the system, for a constant the pressure. pressure, non-flow, mechanically reversible process. 3. Pick out the wrong statement. c. Thermal efficiency of a Carnot engine a. A refriferation cycle violates the second depends upon the properties of the law of thermadynamics. working fluid besides the source & sink b. Refrigeration cycle is normally represented by temperatures. a temperature vs. entropy plot. d. During a reversible adiabatic process, the c. In a refrigerator, work required decreases as entropy of a substance remains constant. the temperature of the refrigerator and the temperature at which heat is rejected 11. Number of components (C), phase (P) and increases. degrees of freedom (F) are related by Gibbs phase d. One ton of refrigeration is equivalent to the rule as rate of heat absorption equal to 3.53 kW. a. P + F - C = 2 b. C = P - F + 2 4. The equation, PV = nRT, is best obeyed by gases at c. F = C - P - 2 a. low pressure & high temperature. d. P = F - C – 2 b. high pressure & low temperature.  THERMODYNAMICS - INDIABIX 12. The value of Cp & Cv respectively for monoatomic a. directly proportional to pressure. gases in Kcal/kg Mole. °K are b. inversely proportional to pressure. a. 5 & 3 c. unity at all pressures. b. 3.987 & 1.987 d. none of these. c. 1.987 & 0.66 d. 0.66 & 1.987 20. Those solutions in which there is no volume change upon mixing the components in the liquid state and which, when diluted do not undergo any heat change (i.e. heat of dilution is zero), are called __________ solutions. 13. is the mathematical expression for a. ideal a. specific heat at constant pressure (Cp). b. real b. specific heat at constant volume (Cv). c. isotonic c. Joule-Thompson co-efficient. d. none of these d. none of these. 21. Generation of heat by friction is an example of a/an 14. In case of a close thermodynamic system, there is __________ change. __________ across the boundaries. a. isothermal a. no heat and mass transfer b. irreversible b. no mass transfer but heat transfer c. adiabatic c. mass and energy transfer d. reversible d. none of these 22. A domestic refrigerator has a/an __________ 15. During a reversible isothermal expansion of an cooled condenser. ideal gas, the entropy change is a. water a. +ve b. air b. 0 c. evaporative c. -ve d. gas d. ∞ 23. The extensive properties are 16. As the temperature is lowered towards the a. volume, mass and number of moles. b. free energy, entropy and enthalpy. absolute zero, the value of , then approaches c. both (a) and (b). a. unity d. none of these. b. zero c. that of the heat of reaction 24. The compressibility factor of a gas is given by d. infinity (where, V1 = actual volume of the gas V2 = gas volume predicted by ideal gas law ) 17. The ratio of equilibrium constants (Kp2/Kp1) at two a. V1/V2 different temperatures is given by b. V2/V1 c. V1-V2 d. V1.V2 a. 25. If we increase the pressure on a substance (which is at its triple point), then the triple point a. increases b. b. decreases c. remains unchanged d. may increase or decrease ; depends on the c. substance 26. In an ideal refrigeration cycle, the change in internal energy of the fluid is d. a. +ve b. -ve 18. Which of the following is not affected by c. 0 temperature changes ? d. either of the above three ; depends on the a. Fugacity nature of refrigerant. b. Activity co-efficient c. Free energy 27. Free energy d. None of these a. decreases in all spontaneous (or irreversible) processes. 19. For an ideal gas, the activity co-efficient is  THERMODYNAMICS - INDIABIX b. change during a spontaneous process has a b. formation negative value. c. dilution c. remains unchanged in reversible processes d. combustion carried at constant temperature and pressure. d. all (a), (b) and (c). 36. The value of Joule-Thomson co-efficient, in case where cooling occurs after the throttling process is 28. "If different processes are used to bring about the a. 0 same chemical reaction, the enthalpy change is same b. ∞ for all of them". This is __________ law. c. +ve a. Hess's d. -ve b. Kirchoff's c. Lavoisier and Laplace 37. Adiabatic compression of a saturated water vapour d. none of these makes it a. supersaturated 29. Fugacity is a measure of the b. superheated a. escaping tendencies of the same c. both (a) and (b) substance in different phases of a system. d. neither (a) nor (b) b. relative volatility of a mixture of two miscible liquids. 38.The specific heat of saturated water vapour at c. behaviour of ideal gases. 100°C is d. none of these. a. ∞ b. -ve 30. The quantitative effect of temperature on chemical c. 0 equilibrium is given by the d. +ve a. Vant-Hoff equation. b. Le-Chatelier's principle. 39. For a multicomponent system, the term chemical c. Arhenius equation. potential is equivalent to the d. none of these. a. molal concentration difference. b. molar free energy. 31. For an irreversible process involving only pressure- c. partial molar free energy. volume work d. molar free energy change. a. (dF)T, p 0 The change in Gibbs free energy for vaporisation of a d. (dA)T, v >0 pure substance is a. positive 32. Ideal refrigeration cycle is b. negative a. same as Carnot cycle. c. zero b. same as reverse Carnot cycle. d. may be positive or negative c. dependent on the refrigerant's properties. d. the least efficient of all refrigeration processes. 41. Critical compressibility factor for all substances a. are more or less constant (vary from 0.2 to 33. The following heat engine produces power of 0.3). 100000 kW. The heat engine operates between 800 K b. vary as square of the absolute temperature. and 300 K. It has a thermal efficiency equal to 50% of c. vary as square of the absolute pressure. that of the Carnot engine for the same temperature. d. none of these. The rate at which heat is absorbed from the hot reservoir is 42. What is the degree of freedom for two mis-cible a. 100, 000 kW (non-reacting) substances in vapor-liquid equilibrium b. 160, 000 kW forming an azeotrope ? c. 200, 000 kW a. 0 d. 320, 000 kW b. 1 c. 2 34. Refrigeration cycle d. 3 a. violates second law of thermodynamics. b. involves transfer of heat from low 43. For a given substance at a specified temperature, temperature to high temperature. activity is __________ to fugacity. c. both (a) and (b). a. directly proportional d. neither (a) nor (b). b. inversely proportional c. equal 35. The enthalpy change when ammonia gas is d. none of these dissolved in water is called the heat of a. solution  THERMODYNAMICS - INDIABIX 44. In case of vapour compression refrigeration SECTION 6 system, elevating the evaporator temperature (keeping 1. The Carnot co-efficient of performance (COP) of a the condenser temperature constant) results in domestic air conditioner compared to a household a. enhanced COP. refrigerator is b. decreased COP. a. less c. no change in the value of COP. b. more d. increased or decreased COP ; depending c. same upon the type of refrigerant. d. dependent on climatic conditions 45. For water at 300°C, it has a vapour pressure 2. The unit of fugacity is the same as that of the 8592.7 kPa and fugacity 6738.9 kPa Under these a. pressure conditions, one mole of water in liquid phase has a b. temperature volume of 25.28 cm3 and that in vapour phase in 391.1 c. volume cm3.Fugacity of water (in kPa) at 9000 kPa will be d. molar concentration a. 6738.9 b. 6753.5 3. Filling of gas from a high pressure cylinder into c. 7058.3 small bottles is an example of a/an __________ d. 9000 process. a. equilibrium 46. __________ equation predicts the activity co- b. adiabatic efficient from experimental data. c. steady a. Lewis-Randall d. unsteady b. Margules c. Van Laar 4. A large iceberg melts at the base, but not at the top, d. both(b)&(c) because of the reason that a. ice at the base contains impurities which 47. As the temperature is lowered towards the lowers its melting point. absolute zero, the value of the b. due to the high pressure at the base, its melting point reduces. c. the iceberg remains in a warmer condition at quantity approaches the base. a. zero d. all (a), (b) and (c). b. unity c. infinity 5. At the critical point of a substance d. none of these a. the surface tension vanishes. b. liquid and vapour have the same density. 48. An ideal liquid refrigerant should c. there is no distinction between liquid and a. not have a subatmospheric vapour pressure at vapour phases. the temperature in the refrigerator coils. d. all (a), (b) and (c). b. not have unduly high vapour pressure at the condenser temperature. 6. A system undergoes a change from a given initial c. both (a) and (b). state to a given final state either by an irreversible d. have low specific heat. process or by a reversible process, then(where, Δ S1 and Δ SR are the entropy changes of the system 49. If the heat of solution of an ideal gas in a liquid is for the irreversible and reversible processes negative, then its solubility at a given partial pressure respectively) varies with the temperature as a. Δ S1 is always < Δ SR a. solubility increases as temperature increases. b. Δ S1 is sometimes > Δ SR b. solubility increases as temperature c. Δ S1 is always > Δ SR decreases. d. Δ S1 is always = Δ SR c. solubility is independent of temperature. d. solubility increases or decreases with 7. What is the value of Joule-Thomson co-efficient for temperature depending on the Gibbs free an ideal gas ? energy change of solution. a. +ve b. -ve 50. In case of a reversible process (following pvn = c. 0 constant), work obtained for trebling the volume (v1 = 1 d. ∞ m3 and v2 3 m3 ) is max imum, when the value of 'n' is a. 0 8. A two stage compressor is used to compress an b. 1 ideal gas. The gas is cooled to the initial temperature c. y = 1.44 after each stage. The intermediate pressure for the d. 1.66 minimum total work requirement should be equal to the  THERMODYNAMICS - INDIABIX __________ mean of P1 and P2.(where, P1 and P2 are b. isothermal initial and final pressures respectively) c. adiabatic a. logarithmic d. none of these b. arithmetic c. geometric 15. Joule-Thomson co-efficient depends on the d. harmonic a. pressure. b. temperature. 9. y = specific heat ratio of an ideal gas is equal to c. both (a) & (b). a. Cp/Cv d. neither (a) nor (b). b. Cp/(CP-R) c. 1 + (R/CV) 16. Free energy change of mixing two liquid d. all (a), (b) and (c) substances is a function of the a. concentration of the constituents only. 10. Consider the process A & B shown in the figure b. quantities of the constituents only. given below c. temperature only. d. all (a), (b) and (c). 17. Pick out the wrong statement. a. System (of partially miscible liquid pairs), in which the mutual solubility increases with rise in temperature, are said to possess an upper consolute temperature. b. Systems, in which the mutual solubility increases with decrease in temperature, are said to possess lower consolute temperature. c. Nicotine-water system shows both an upper as well as a lower consolute In this case, it is possilbe that temperature, implying that they are partially a. both the processes are adiabatic. miscible between these two limiting b. both the processes are isothermal. temperatures. c. process A is isothermal while B is d. none of these adiabatic. d. process A is adiabatic while B is isothermal. 18. The total change in the enthalpy of a system is independent of the 11. Gibbs free energy of a pure fluid approaches a. number of intermediate chemical reactions __________ as the pressure tends to zero at constant involved. temperature. b. pressure and temperature. a. infinity c. state of combination and aggregation in the b. minus infinity beginning and at the end of the reaction. c. zero d. none of these. d. none of these 19. Number of phases in a colloidal system are 12. As the entropy of the universe is increasing, day by a. 1 day, the work producing capacity of a heat engine is b. 2 a. not changed c. 3 b. decreasing d. 4 c. increasing d. data sufficient, can't be predicted 20. Free energy changes for two reaction mechanism 'X' and 'Y are respectively - 15 and - 5 units. It implies 13. An irreversible process that X is a. is the analog of linear frictionless motion in a. slower than Y machines. b. faster than Y b. is an idealised visualisation of behaviour of a c. three times slower than Y system. d. three times faster than Y c. yields the maximum amount of work. d. yields an amount of work less than that of a 21. Vapour which is at a pressure smaller than the reversible process. saturation pressure for the temperature involved is called a __________ vapour. 14. The expression for the work done for a reversible a. superheated polytropic process can be used to obtain the b. desuperheated expression for work done for all processes, except c. non-condensable reversible __________ process. d. none of these a. isobaric  THERMODYNAMICS - INDIABIX 22. At equilibrium condition, the chemical potential of a b. chemical potential material in different phases in contact with each other c. molal boiling point is equal. The chemical potential for a real gas (μ) is d. heat capacity given by(where, μ = standard chemical potential at unit fugacity (f° = 1 atm.) and the gas behaves ideally.) 31. Gibbs free energy at constant pressure and a. μ° + RT ln f temperature under equilibrium conditions is b. μ°+ R lnf a. ∞ c. μ° + T lnf b. 0 d. μ° + R/T lnf c. maximum d. minimum 23. The kinetic energy of gas molecule is zero at a. 0°C 32. With increase in pressure (above atmospheric b. 273°C pressure), the Cp of a gas c. 100°C a. increases d. -273°C b. decreases c. remains unchanged 24. Which of the following is not an intensive property d. first decreases and then increases ? a. Volume 33. A change in state involving a decrease in entropy b. Density can be spontaneous, only if c. Temperature a. it is exothermic. d. Pressure b. it is isenthalpic. c. it takes place isothermally. 25. The necessary and sufficient condition for d. it takes place at constant volume. equilibrium between two phases is a. the concentration of each component should 34. Joule-Thomson co-efficient which is defined be same in the two phases. b. the temperature of each phase should be same. c. the pressure should be same in the two as, , changes sign at a phases. temperature known as inversion temperature. The d. the chemical potential of each component value of Joule-Thomson co-efficient at inversion should be same in the two phases. temperature is a. 0 26. Specific volume of an ideal gas is b. ∞ a. equal to its density. c. +ve b. the reciprocal of its density. d. -ve c. proportional to pressure. d. none of these. 35. __________ calorimeter is normally used for measuring the dryness fraction of steam, when it is 27. Pick out the extensive property out of the following. very low. a. Surface tension a. Bucket b. Free energy b. Throttling c. Specific heat c. Separating d. Refractive index d. A combination of separating & throttling 28. Entropy change of the reaction, 36. The amount of heat required to decompose a H2O(liquid) H2O(gas), is termed as the enthalpy of compound into its elements is __________ the heat of a. solution formation of that compound from its elements. b. vaporisation a. less than c. formation b. more than d. formation c. same as d. not related to 29. Which law of the thermodynamics provids basis for measuring the thermodynamic property ? 37. For a constant volume process a. First law a. dE = CpdT b. Zeroth law b. dE = CvdT c. Third law c. dQ = dE + pdV d. Second law d. dW = pdV 30. Gibbs free energy per mole for a pure substance is 38. In case of the decomposition of hydroiodic acid equal to the (2HI H2 + I2), addition of H2 (at equilibrium a. latent heat of vaporisation condition) will  THERMODYNAMICS - INDIABIX a. increase the partial pressure of I2. b. composition b. decrease the partial pressure of HI. c. temperature c. diminish the degree of dissociation of HI. d. all (a), (b) and (c) d. none of these. 48. Pick out the wrong statement: 39. In any spontaneous process, the __________ free a. The expansion of a gas in vacuum is an energy decreases. irreversible process. a. Helmholtz b. An isometric process is a constant b. Gibbs pressure process. c. both a & b c. Entropy change for a reversible adiabatic d. neither 'a' nor 'b' process is zero. d. Free energy change for a spontaneous 40. The gas law (PV = RT) is true for an __________ process is negative. change. a. isothermal 49. With increase in compression ratio, the efficiency b. adiabatic of the otto engine c. both (a) & (b) a. increases d. neither (a) nor (b) b. decreases c. remains constant 41. The equation DU = Tds – PdV is applicable to d. increases linearly infinitesimal changes ccurring in a. an open system of constant composition. 50. The chemical potential of any constituent of an b. a cl