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Question Bank No: 1

1. During isothermal expansion of an ideal gas,its

a)		Internal energy increases
b)		enthalphy increases
c)		enthalphy reduces to zero
d)		enthalphy remains unchanged

2. If K<1.0,what will be the value of $Δ G^{0}$ of the following

a)		1.0
b)		Zero
c)		Negative
d)		Positive

3. The latent heat of vaporisation of a liquid at 500 K and 1 atm pressure is 10.0 kcal ${mol}^{- 1} .$ The intenal energy change of 3 mol of liquid at the same temperature and pressure is

a)		30 keal
b)		27 keal
c)		33 keal
d)		13 keal

4. 2.8 L of $N_{2}$ gas at 300 K and 20 atm was allowed to expand isothermally against the external pressure of 1 atm.The value of $Δ$ U of the process is

a)		10 J
b)		0
c)		-10 J
d)		4.18 J

5. Enthalphy of combustion of liquid benzene is -3264.6kJ ${mol}^{- 1} .$ The heat produced by burning 3.9g of benzene is

a)		$\frac{3264.6}{78} kJ$
b)		$\frac{3264.6}{20} kJ$
c)		$\frac{3264.6}{3.9} kJ$
d)		3264.6kJ

6. The bond dissociation enthalpies of $H_{2}, {Cl}_{2},$ and HCl are 104,58, and 103 keal respectively.The ethalphy of formation of HCl gas will be

a)		-44 kcal
b)		-88 kcal
c)		-22 kcal
d)		-11 kcal

7. When 0.1 mole of a gas absorbs 41.75 J of heat, the rise in temperature occurs equal to $20^{0} C .$ The gas must be

a)		triatomic
b)		diatomic
c)		polyatomic
d)		monoatomic

8. In $C_{2} H_{4}$ the bond enthalpies of (C=C) and (C-C) bonds are -590 kJ/mole and -331 kJ/mole respectively.What is enthalphy change when one mole of ethylene polymerizes to form polythene?

a)		+259 kJ ${mol}^{- 1}$
b)		+72 kJ ${mol}^{- 1}$
c)		-259 kJ ${mol}^{- 1}$
d)		-72 kJ ${mol}^{- 1}$

9. The molar heat capacity of Al is 27.0 J ${mol}^{- 1} K^{- 1}$ The heat absorbed by the aluminium sheet of 6 kg mass placed in sun which shows increase in its temperature from $25^{0} C$ to $45^{0} C$ is

a)		60kJ
b)		120kJ
c)		240kJ
d)		392.4kJ

10. Work done in vaporisation of one mol of water at 373 K against the pressure of 1 atmospher is approximately.

a)		-3100.0J
b)		31.20 J
c)		-20.2 J
d)		+20.2 J

11. The internal energy change( $Δ$ U)of a process does not depend upon

a)		Amount of substance undergoing the change
b)		temperature
c)		path of the process
d)		nature of substance undergoing the change

12. For the reaction. ${3 O}_{2} (g) \to {2 O}_{3} (g)$ the sign of $Δ$ G and $Δ$ S respecrively are

a)		+ve and -ve
b)		+ve and +ve
c)		-ve and -ve
d)		-ve and +ve

13. One mole of ideal gas expands freely at 310 K from five litre volume to 10 litre volume.Then $Δ$ U and $Δ$ H of the process are respectively

a)		0 and 5 cal
b)		0 and 5 $\times$ 300 cal
c)		0 and 0
d)		5 and 0 cal

14. The mixing of gases is generally accompained by

a)		Decrease in entropy
b)		decrease in free energy
c)		change in heat content
d)		increase in free energy

15. One mole of $H_{2} {SO}_{4}$ is completely neutralised with 2 moles of NaOH in dilute solutions.The amount of heat evolved during the process is

a)		57.0kJ
b)		>57.0kJ
c)		<57.0kJ
d)		>114.0kJ

16. Enthalphy of neutralisation of acetic acid with KOH will be numerically

a)		=57.1kJ
b)		>57.1kJ
c)		<57.1kJ
d)		unpredicted

17. Internal energy of a given mass of an ideal depends upon

a)		Temperature
b)		Pressure
c)		Volume
d)		On all the above factors

18. Which of the following is true for an adiabatic process?

a)		$Δ H = 0$
b)		$Δ W = 0$
c)		$Δ Q = 0$
d)		$Δ V = 0$

19. The ratio of $\frac{C_{p}}{C_{v}}$ for inert gas is

a)		1.33
b)		1.66
c)		2.13
d)		1.99

20. The value of R in calorine per degree per mole is

a)		0.0831
b)		8.31
c)		8.31 $\times 10^{7}$
d)		1.987

21. The lattice enthalpy and hydration enthalpy of four compounds are given below
$\begin{matrix} Compound & Lattice enthalpy & Hydration enthalpy \\ (in kj {mol}^{- 1}) & (in kj {mol}^{- 1}) \\ P & + 780 & - 920 \\ Q & + 1012 & - 812 \\ R & + 828 & - 878 \\ S & + 632 & - 600 \end{matrix}$
The pair of compounds which is solubale in water is

a)		P and Q
b)		Q ans R
c)		R and S
d)		P and R

22. Using the following thermochemical equations
i)S(rh)+3/2 $O_{2} (g)$ $\to {SO}_{3} (g) Δ H = - 2 \times$ kJ ${mol}^{- 1}$ ....(1)
ii)S $O_{2} (g)$ $+ 1 / 2 O_{2} (g) \to {SO}_{3} (g) Δ H = - ykJ$ ${mol}^{- 1}$ ....(2)
Find out the heat of formation of ${SO}_{2} (g)$ in kJ ${mol}^{- 1}$

a)		(2x+y)
b)		(x+y)
c)		(y-2x)
d)		(2x-y)

23. Change the internal energy,when 4kJ of work is done on the system and 1kJ of heat is given out by the system is

a)		-5kJ
b)		+5kJ
c)		+3kJ
d)		-3kJ

24. Solubility curve of a hydrated salt in water with temperature is given.The curve indicates the solution process is
termodynamic-q20

a)		exothermic
b)		exothermic till $60^{0}$ and endothermic after $60^{0}$ C
c)		endothermic till $60^{0}$ and exothermic thereafter
d)		endothermic

25. The bond dissociation energies of $H_{2}$ , ${Cl}_{2}$ and HCl are 104,58 and 103 kcal ${mol}^{- 1}$ .respectively.The enthalpy of formation of HCl would be

a)		-22kcal. ${mol}^{- 1}$
b)		-44kcal. ${mol}^{- 1}$
c)		+44kcal. ${mol}^{- 1}$
d)		-22kcal. ${mol}^{- 1}$

26. The decomposition of limestone ${CaCO}_{3 (s)} \overset{⇀}{↽}$ $CaO (s) + {CO}_{2 (g)}$ is non spontaneous at 298.The ${Δ H}^{0}$ and ${Δ S}^{0}$ values for the reaction are 176.0 kJ and 160 ${JK}^{- 1}$ respectively.At what temperature the decomposition becomes spontaneous?

a)		at 1000 K
b)		below $500^{0} C$
c)		at $500^{0} C$
d)		above $827^{0} C$

27. If 150kJ of energy is needed for muscular work to walk a distance of one km, then how much glucose one has to consume to walk a distance of one km, then how much glucose one has to consume to walk a distance of five km, provided only 30% of energy available for muscular work.The enthalpy of combustion of glusoce is 3000kJ ${mol}^{- 1}$

a)		75g
b)		30g
c)		180g
d)		150g

28. For the reaction CO(g) +1/2 $O_{2} (g), Δ H$ and $Δ S$ are - 283kJ and -87 ${JK}^{- 1},$ respectively.It was intended to carry out this reaction at 1000,1500,3000 and 3500 K.At which of these temperatures would this reaction be thermodynamically spontaneous?

a)		1500 and 3500 K
b)		3000 and 3500 K
c)		1000,1500 and 3000 K
d)		1500,3000 and 3500 K

29. Which one of the following equations does NOT correctly represent the first law thermodynamics for the given processes?

a)		Isothermal process : q=-w
b)		Cyclic process : q=-w
c)		Isochoric process : q =-w
d)		Adiabatic process : q=-w

30. We can drive any thermodynamically forbidden reaction in the desired direction by coupling with

a)		Highly exothermic reaction
b)		Highly endothermic reaction
c)		Highly exergonic reaction
d)		Highly endoergonic reaction

31. For the homogeneous reaction xA +yB $\overset{⇀}{↽}$ 1Y +mZ
$Δ H^{0}$ =30KJ ${mol}^{- 1}$ and $Δ S = - 100 JK$ ${mol}^{- 1}$
At what temperature the reaction the reaction is at equilibrium?

a)		$50^{0} C$
b)		$25^{0} C$
c)		100K
d)		$27^{0} C$

32. Consider the following reaction at $1000^{0} C$
a)Zn(s) + $\frac{1}{2} O_{2} (g) \to$ ZnO(s); $Δ G^{0} = - 360$ ${kJ mol}^{- 1}$
b)C(gr) + $\frac{1}{2} O_{2} (g) \to$ CO(g); $Δ G^{0} = - 460$ ${kJ mol}^{- 1}$
Choose the correct statement (At $1000^{0} C)$

a)		Zinc can be oxidized by carbon monoxide
b)		Zinc oxide can be reduced by graphite
c)		Both statements (a) and (b) are true
d)		Carbon monoxide can be reduced by zinc

33. What would be the heat released when an aqueous solution containing 0.5 mole of ${HNO}_{3}$ is mixed with 0.3 mole of ${OH}^{-}$ (Enthalpy of neutralization is -57.1kJ)?

a)		28.5kJ
b)		17.1kJ
c)		45.7kJ
d)		1.7kJ

34. $Δ H$ and $Δ S$ for a reaction are +30.558 kJ ${mol}^{- 1}$ and 0.066 k ${JK}^{- 1} {mol}^{- 1}$ at 1 atm pressure.The temperature at which free energy change is equal to zero and the nature of the reaction below this temperature are

a)		483 K, spontaneous
b)		443 K, non-spontaneous
c)		463 K, non-spontaneous
d)		463 K, spontaneous

35. Five moles of a gas is put through a series of changes shown graphically in a cyclic process. The process during A $\to$ B. B $\to C$ and C $\to A$ respectively are
termodynamic-q9

a)		isochoric, isobaric, isothermal
b)		isobaric, isochoric, isothermal
c)		isothermal, isobaric, isochoric
d)		isobaric, isothermal, isochoric

36. One mole of an ideal gas is expanded freely and isothermally at 300 K from 10 litres to 100 litres.If $Δ E = 0$ the value of $Δ H is$

a)		10 KJ
b)		200 KJ
c)		-200KJ
d)		Zero

37. Values of $Δ H$ and $Δ S$ for five different reactions are given below
$\begin{matrix} Reactions & Δ H (kJ {mol}^{- 1}) & Δ S ({JK}^{- 1} {mol}^{- 1}) \\ 1 & + 98.0 & + 14.8 \\ 11 & - 55.5 & - 84.6 \\ 111 & + 28.3 & - 17.0 \\ 1 V & - 40.5 & + 24.6 \\ V & + 34.7 & 0.0 \end{matrix}$
On the basis of these values predict which one of these will be spontaneous at all temperature?

a)		Reaction 1
b)		Reaction 11
c)		Reaction 111
d)		Reaction 1V

38. A cylinder of gas supplied by Bharat petroleum is assumed to contain 14 kg of butane. If a normal family requires 20,000 kJ of energy per day for cooking, butane gas in the cylinder last for...Days( $Δ H_{c}$ of $C_{4} H_{10} = - 2650 KJ$ per mole)

a)		15 days
b)		20 days
c)		40 days
d)		32 days

39. The difference between heats of reaction at constant pressure and constant volume for the reaction
${{2 C}_{6} H}_{6 (1)} + 150_{2} (g) \to {12 CO}_{2} (g) + {6 H}_{2} O_{1} at 25^{0} C$ in kJ ${mol}^{- 1}$ is

a)		-7.43
b)		+3.72
c)		-3.72
d)		+7.43

40. In thermodynamics which one of the following is not an intensive property

a)		Pressure
b)		Density
c)		Volume
d)		Temperature

41. The enthalpy of vaporisation of a substance is 840J. ${mol}^{- 1}$ and its boiling points is - $173^{0} C .$ Its entropy of vaporization is

a)		42J. ${mol}^{- 1} . K^{- 1}$
b)		21J. ${mol}^{- 1} . K^{- 1}$
c)		84J. ${mol}^{- 1} . K^{- 1}$
d)		8.4J. ${mol}^{- 1} . K^{- 1}$

42. The value of $Δ H - Δ E$ for the following reaction at $27^{0} C$ will be, ${2 NH}_{3 (g)} \to N_{2 (g)} + {3 H}_{2 (g)}$

a)		8.314 $\times 273 \times (- 2)$
b)		8.314 $\times 300 \times (- 2)$
c)		8.314 $\times 27 \times (- 2)$
d)		8.314 $\times 300 \times (2)$

43. The free energy change for the following reactions are given below
$C_{2} H_{2} (g) + \frac{5}{2} O_{2} (g) \to {2 CO}_{2} (g) + H_{2} O (1) Δ G^{0} = 1234 kJ ... (1)$
$C (s) + O_{2} (g) \to {CO}_{2} (g) Δ G^{0} = - 394 kJ ... (2)$
$H_{2} (g) + \frac{1}{2} O_{2} (g) \to H_{2} O (I) + H_{2} O (1) Δ G^{0} = - 234 kJ ... (3)$
What is the standard free energy change for the reaction $H_{2} (g) + {2 C}_{(s)} \to C_{2} H_{2} (g) ?$

a)		-209kJ
b)		-2259kJ
c)		+2259kJ
d)		209kJ

44. $N_{2} + {2 O}_{2} \to {2 NO}_{2} + XKJ$
2NO + $O_{2} \to {2 NO}_{2} + YKJ$
The enthalpy of formation of No is

a)		2X -2Y
b)		X - Y
c)		$\frac{1}{2} (Y - X)$
d)		$\frac{1}{2} (X - Y)$

45. For a process to occur under adiabatic conditions

a)		$Δ T = 0$
b)		$Δ P = 0$
c)		$δ q = 0$
d)		$δ w = 0$

46. Which of the following is an intensive Property

a)		Volume
b)		Mass
c)		Density
d)		Energy

47. C (diamond) $\to C (Graphite), Δ H = - ve .$ This shows that

a)		Graphite is more stable than diamond
b)		Graphite has more stableenergy than diamond
c)		Both are equal stable
d)		Stability cannot be predicted

48. For a melting of a solid at $25^{\circ} C,$ the fusion process requires energyequivalent to 2906 Joules to be added to system considering the process to be reversible at fusion point, the entropy change of the process is

a)		9.75 JK -1
b)		11.272 JK -1
c)		2.33 JK -1
d)		insufficient data

49. Which of the following holds good to the laws of thermodynamics for the reaction $C_{2} H_{4} (g) + 30_{2} (g) \to 2 C O_{2} (g) + 2 H_{2} 0$

a)		$Δ H = Δ E + RT$
b)		$Δ H = Δ E - RT$
c)		$Δ H = Δ E + 2 RT$
d)		$Δ H = Δ E - 2 RT$

50. $Δ H$ for solid to liquid transitions for protein A and Bare 2.73 keal and 3.0 kcal/ mol. The two melting points are $0^{\circ} C$ and 3 $0^{\circ} C$ respectively. The entropy changes $Δ S_{A}$ and $Δ S_{B}$ at two transition temperature are related as

a)		$Δ S_{A} = Δ S_{B}$
b)		$Δ S_{A} < Δ S_{B}$
c)		$Δ S_{B} < Δ S_{A}$
d)		$Δ S_{B} = \frac{300 Δ S_{A}}{273}$