MCQ Questions For Class 11 Chemistry Chapter 6 Thermodynamics

Please refer to MCQ Questions Thermodynamics for Chapter 6 Class 11 Chemistry given below. All MCQ questions are provided with answers. These MCQ Questions for Class 11 Chemistry are designed based on the chapters given in your CBSE NCERT Textbook for Class 11 Chemistry. These MCQ Questions are expected to come in your class 11 Board exams.

Question. Which of the following is the correct equation?
(a) ΔU = ΔW + DQ
(b) ΔU = ΔQ – W
(c) ΔW = ΔU + ΔQ
(d) None of these

Question. The correct option for free expansion of an ideal gas under adiabatic condition is
(a) q = 0, ΔT = 0 and w = 0
(b) q = 0, ΔT < 0 and w > 0
(c) q < 0, ΔT = 0 and w = 0
(d) q > 0, ΔT > 0 and w > 0 

Question. Under isothermal conditions, a gas at 300 K expands from 0.1 L to 0.25 L against a constant external pressure of 2 bar. The work done by the gas is [Given that 1 L bar = 100 J]
(a) 30 J
(b) –30 J
(c) 5 kJ
(d) 25 J

Question. An ideal gas expands isothermally from 10^–3 m³ to 10^–2 m³ at 300 K against a constant pressure of 10⁵ N m^–2. The work done on the gas is
(a) +270 kJ
(b) –900 J
(c) +900 kJ
(d) –900 kJ

Question. Which of the following are not state functions?
(I) q + w (II) q
(III) w (IV) H – TS
(a) (I), (II) and (III)
(b) (II) and (III)
(c) (I) and (IV)
(d) (II), (III) and (IV)

Question. In a closed insulated container a liquid is stirred with a paddle to increase the temperature, which of the following is true?
(a) ΔE = W ≠ 0, q = 0
(b) ΔE = W = q ≠ 0
(c) ΔE = 0, W = q ≠ 0
(d) W = 0, ΔE = q ≠ 0

Question. Which of the following is correct option for free expansion of an ideal gas under adiabatic condition?
(a) q = 0, ΔT ≠ 0, w = 0
(b) q ≠ 0, ΔT = 0, w = 0
(c) q = 0, ΔT = 0, w = 0
(d) q = 0, ΔT < 0, w ≠ 0

Question. Three moles of an ideal gas expanded spontaneously into vacuum. The work done will be
(a) infinite
(b) 3 Joules
(c) 9 Joules
(d) zero.

Question. Assume each reaction is carried out in an open container. For which reaction will ΔH = ΔE?
(a) 2CO_(g) + O_2(g) → 2CO_2(g)
(b) H_2(g) + Br_2(g) → 2HBr_(g)
(c) C(s) + 2H₂O_(g) → 2H₂(g) + CO_2(g)
(d) PCl_5(g) → PCl_3(g) + Cl_2(g) 

Question. A gas is allowed to expand in a well insulated container against a constant external pressure of 2.5 atm from an initial volume of 2.50 L to a final volume of 4.50 L. The change in nternal energy DU of the gas in joules will be
(a) –500 J
(b) –505 J
(c) +505 J
(d) 1136.25 J

Question. Equal volumes of two monatomic gases, A and B at same temperature and pressure are mixed. The ratio of specific heats (CP/CV) of the mixture will be
(a) 0.83
(b) 1.50
(c) 3.3
(d) 1.67

Question. Heat required to raise the temperature of I mole of a substance by 1° is called
(a) specific heat
(b) molar beat capacity
(c) water equivalent
(d) specific gravity     

Question. Which of the following is a path fonction? 
(a) Internal energy
(b) Enthalpy
(c) Work
(d) Entropy   

Question. Hess’s law states that 
(a) the standard enthalpy ofan overall reaction is the sum of the enthalpy changes in individual reactions
(b) enthalpy of formation of a compound is same as the enthalpy of decomposition of the compound into constituent elements, but with opposite sign
(c) at constant temperature the pressure of a gas is inversely proportional to its volume
(d) the mass of a gas dissolved per litre of a solvent is proportional to the pressure of the gas in equilibrium with the solution.   

Question. Based on the first law of thermodynamics, which one of the following is correct ? 
(a) For an isochoric process= ΔE = – Q
(b) For an adiabatic process = ΔE = – W
(c) For an isothermal process = Q = + W
(d) For a cyclic process = Q = – W       

Question. C₂H₂ + 5/2 O₂ → 2CO₂ + H₂O ; ΔH = –310 kcal 
C+O₂ → CO2; ΔH = –94 kcal 
H2 + 1/2 O₂ → H2O; ΔH = –68 kcal
On the basis of the above equations, ΔH_f (enthalpy of fom1ation) of C₂H₂ will be 
(a) –148 kcal
(b) + 54 kcal
(c) –54 kcal
(d) + 80 kcal     

Question. Which of the following is an intensive property? 
(a) Temperature
(b) Viscosity
(c) Surface tension
(d) All of these       

Question. Which is an extensive property?
(a) Temperature
(b) Chemical potential
(c) Gibb’s free energy
(d) Molar volume     

Question. Which of the following taking place in the blast furnace is endothennic ? 
(a) CaCO₃ → CaO+ CO₂
(b) 2C+ O₂ → 2CO
(c) C + O₂ → CO₂
(d) Fe₂O₃ + 3CO → 2Fe + 3CO₂     

Question. When 0. 2 g of 1-butanol was burnt in a suitable apparatus, the heat evolved was sufficient to raise the temperature of 200 g water by 5°C. The enthalpy of combustion of 1-butanol in kcal mol^-1 will be 
(a) + 37
(b) + 370
(c) –370
(d) –740     

Question. How many joules of beat are absorbed when 70. O g of water is completely vaporised at its boiling point ? ( L_v = 2260 kJ/kg) 
(a) 23352
(b) 7000
(c) 15813
(d) 158200     

Question. The work done during the expansion of a gas from a volume of 4 dm3 to 6 dm3 against a constant external pressure of 3 atm is (1 L atm = 101.32 J)
(a) – 6 J
(b) – 608 J
(c) + 304 J
(d) – 304 J 

Question. When 1 mol of gas is heated at constant volume temperature is raised from 298 to 308 K. Heat supplied to the gas is 500 J. Then which statement is correct?
(a) q = w = 500 J, ΔE = 0
(b) q = ΔE = 500 J, w = 0
(c) q = w = 500 J,ΔE = 0
(d) ΔE = 0, q = w = –500 J

Question. For the reaction, C₂H₅OH_(l) + 3O_2(g) → 2CO_2(g) + 3H₂O_(l) which one is true?
(a) ΔH = ΔE – RT
(b) ΔH = ΔE + RT
(c) ΔH = ΔE + 2RT
(d) ΔH = ΔE – 2RT 

Question. In an endothermic reaction, the value of ΔH is
(a) negative
(b) positive
(c) zero
(d) constant. 

Question. One mole of an ideal gas at 300 K is expanded isothermally from an initial volume of 1 litre to 10 litres. The ΔE for this process is (R = 2 cal mol^–1 K^–1)
(a) 1381.1 cal
(b) zero
(c) 163.7 cal
(d) 9 L atm 

Question. During isothermal expansion of an ideal gas, its
(a) internal energy increases
(b) enthalpy decreases
(c) enthalpy remains unaffected
(d) enthalpy reduces to zero. 

Question. In equilibrium state the value of AG is
(a) zero
(b) negative
(c) positive
(d) may be negative or positive   

Question. Entropy of the universe is
(a) constant
(b) zero
(c) continuously decreasing
(d) continuously increasingVVVD   

Question. What will be the temperature at which
ΔG = -5.2kJ mol^-1, ΔH = 145.6 kJ mol^-1 and
ΔS = 216JK^-1 mol^-1 for a chemical reaction?
(a) 650 K
(b) 425°C 
(c) 525 K
(d) 625°C     

Question. In a fuel cell methanol is used as fuel and oxygen gas is used as an oxidiser. The reaction is
CH₃OH(/) + 3/2 O₂(g) ➔ CO₂ (g)+2H₂ O(/).
At 298 K standard Gibb’s energies of fo1mation for CH₃OH(/), H₂O(/) and CO₂ (g) are-166.2, -237.2 and -394.4 kJ mol^-1 respectively. If standard enthalpy of combustion of methanol is -726kJ mol^-1 , efficiency of the fuel cell will be 
(a) 80%
(b) 87%
(c) 90%
(d) 97%     

Question. For a reaction ΔH = (+3 kJ),ΔS = (+ l0 J/K) beyond which temperature this reaction will be spontaneous ?
(a) 300 K
(b) 200 K
(c) 273 K
(d) 373 K   

Question. For the process H₂O(/) → H₂O(g) at T = 1000° Cand 1 atmosphere pressure, the con-ect choice is 
(a) ΔS_system > 0 and ΔS_system > 0
(b) ΔS_system > 0 and ΔS_system < 0
(c) ΔS_system < 0 and ΔS_system > 0
(d) ΔS_system < 0 and ΔS_system < 0   

Question. At 298 K the entropy of rhombic sulphur is 32.04 J/mol K and that of monoclinic sulphur is 32.68 J/mol K. The heat of their combustion are respectively -298246 and -297948 J mol^-1 .ΔG for the reactions; S_rhombic → S_monoclinic will be 
(a) 107.28 J
(b) 10.728 J
(c) 107.28 kJ
(d) 10728 J     

Question. In which of the following process, maximum increase in entropy is observed ? 
(a) Melting of ice
(b) Sublimation of naphthalene
(c) Condensation of water
(d) Dissolution of salt in water   

Question. Considering the reaction,
C(s) + O₂ (g) → CO₂ (g)+393.5 kJ the signs of ΔH , ΔS and AG respectively are
(a) +, – , –
(b) -, +, +
(c) – , – , –
(d) – ,+, –   

Question. In which reaction there will be increase in entropy? 
(a) Na(s) + H₂O(l) → NaOH(/)+ 1/2H₂ (g)
(b) Ag⁺ (aq) + Cl^– (aq) → AgCl(s)
(c) H₂ (g) + 1/2 O₂ (g) → H₂0(/)
(d) Cu²⁺ (aq) + 4NH₃ (g) → [Cu(NH₃)₄]²⁺ (aq) 

Question. I₂ (s) ⇌ 12 (g); ΔH = + 40 kcal, ΔS = 80 cal. The sublimation point of I₂ (s) will be 
(a) 100°C
(b) 127°C
(c) 227°C
(d) 500°C 

Question. For an ideal binary liquid mixture 
(a) ΔS (_mix) = 0; ΔG (_mix) = 0
(b) ΔH (_mix) = 0; ΔS (_mix) < 0
(c) ΔV (_mix) = 0; ΔG (_mix) > 0
(d) ΔS (_mix) > 0; ΔG (_mix) < 0          

Question. For a reversible reaction,
X(g) + 3Y(g) ⇌ 2Z(g); ΔH = – 40 kJ, the standard entropies of X, Y and Z are 60, 40 and 50 JK^-1 mol^-1 respectively. The temperature at which the above reaction attains equilibrium is about
(a) 400 K
(b) 500 K
(c) 273 K
(d) 373 K   

Question. The latent heat of fusion of ice at 0° C is 80 cal/g. Entropy change (ΔS) accompanying the melting of 1 g of ice at 0° C would be (units cal/g/K) 
(a) 273
(b) 8.0
(c) 0.9
(d) 0.293 

Question. For the reaction, C₃H_8(g) + 5O_2(g) → 3CO_2(g) + 4H₂O_(l) at constant temperature, ΔH – ΔE is
(a) + RT
(b) –3RT
(c) +3RT
(d) –RT

Question. The molar heat capacity of water at constant pressure, C , is 75 J K^–1 mol^–1. When 1.0 kJ of heat is supplied to 100 g of water which is free to expand, the increase in temperature f water is
(a) 1.2 K
(b) 2.4 K
(c) 4.8 K
(d) 6.6 K 

Question. For which one of the following equations is DH°reaction equal to ΔH°f for the product?
(a) N_2(g) + O_3(g) → N₂O_3(g)
(b) CH4_(g) + 2Cl_2(g) → CH₂Cl_2(l) + 2HCl_(g)
(c) Xe_(g) + 2F_2(g) → XeF_4(g)
(d) 2CO_(g) + O2_(g) → 2CO_2(g) 

Question. Heat of combustion ΔH for C_(s), H_2(g) and CH_4(g) are –94, –68 and –213 kcal/mol, then ΔH for C_(s) + 2H_2(g) → CH_4(g) is
(a) –17 kcal
(b) –111 kcal
(c) –170 kcal
(d) –85 kcal

Question. Change in enthalpy for reaction, 2H₂O_2(l) → 2H₂O_(l) + O_2(g) if heat of formation of H₂O_2(l) and H₂O_(l) are –188 and –286 kJ/mol respectively, is
(a) –196 kJ/mol
(b) +196 kJ/mol
(c) +948 kJ/mol
(d) –948 kJ/mole 

Question. Enthalpy of CH4 + 1/2 O₂ → CH₃OH is negative. If enthalpy of combustion of CH₄ and CH₃OH are x and y respectively, then which relation is correct?
(a) x > y
(b) x < y
(c) x = y
(d) x ≥ y

Question. If enthalpies of formation for C2H_4(g), CO_2(g) and H₂O_(l) at 25°C and 1 atm pressure are 52, – 394 and – 286 kJ/mol respectively, then enthalpy of combustion of C₂H_4(g) will be               
(a) + 141.2 kJ/mol 
(b) + 1412 kJ/mol
(c) – 141.2 kJ/mol
(d) – 1412 kJ/mol

Question. If ΔH is the change in enthalpy and ΔE, the change in internal energy accompanying a gaseous reaction, then
(a) ΔH is always greater than ΔE
(b) ΔH < ΔE only if the number of moles of the products is greater than the number of moles of the reactants
(c) ΔH is always less than ΔE
(d) ΔH < ΔE only if the number of moles of products is less than the number of moles of the reactants.

Question. Standard enthalpy of vaporisation DvapH° for water at 100°C is 40.66 kJ mol^–1. The internal energy of vaporisation of water at 100°C (in kJ mol^–1) is
(a) +37.56
(b) – 43.76
(c) + 43.76
(d) + 40.66
(Assume water vapour to behave like an ideal gas)

Question. Bond dissociation enthalpy of H₂, Cl₂ and HCl are 434, 242 and 431 kJ mol^–1 respectively. Enthalpy of formation of HCl is
(a) –93 kJ mol^–1
(b) 245 kJ mol^–1
(c) 93 kJ mol^–1
(d) –245 kJ mol

Question. Given that bond energies of H – H and Cl – Cl are 430 kJ mol–1 and 240 kJ mol^–1 respectively and DHf for HCl is –90 kJ mol–1, bond enthalpy of HCl is
(a) 380 kJ mol^–1
(b) 425 kJ mol^–1
(c) 245 kJ mol^–1
(d) 290 kJ mol^–1

Question. The absolute enthalpy of neutralisation of the reaction : MgO_(s) + 2HCl_(aq) → MgCl_2(aq) + H2O_(l) will be
(a) –57.33 kJ mol^–1
(b) greater than –57.33 kJ mol^–1
(c) less than –57.33 kJ mol^–1
(d) 57.33 kJ mol^–1 

Question. If the bond energies of H–H, Br–Br, and H–Br are 433, 192 and 364 kJ mol^–1 respectively, the ΔH° for the reaction H_2(g) + Br_2(g) → 2HBr_(g) is
(a) –261 kJ
(b) +103 kJ
(c) +261 kJ
(d) –103 kJ

Question. The bond dissociation energies of X₂, Y₂ and XY are in the ratio of 1 : 0.5 : 1. DH for the formation of XY is –200 kJ mol^–1. The bond dissociation energy of X₂ will be
(a) 200 kJ mol^–1
(b) 100 kJ mol^–1
(c) 800 kJ mol^–1
(d) 400 kJ mol^–1

Question. The heat of combustion of carbon to CO₂ is –393.5 kJ/mol. The heat released upon formation of 35.2 g of CO₂ from carbon and oxygen gas is None
(a) + 315 kJ
(b) – 630 kJ
(c) – 3.15 kJ
(d) – 315 kJ

Question. For a given reaction, ΔH = 35.5 kJ mol–1 and DS = 83.6 J K–1 mol^–1. The reaction is spontaneous at (Assume that ΔH and ΔS do not vary with temperature.)
(a) T > 425 K
(b) all temperatures
(c) T > 298 K
(d) T < 425 K

Question. The correct thermodynamic conditions for the spontaneous reaction at all temperatures is
(a) ΔH < 0 and ΔS > 0
(b) ΔH < 0 and ΔS < 0
(c) ΔH < 0 and ΔS = 0
(d) ΔH > 0 and ΔS < 0

Question. Which of the following statements is correct for the spontaneous adsorption of a gas?
(a) ΔS is negative and, therefore ΔH should be highly positive.
(b) ΔS is negative and therefore, ΔH should be highly negative.
(c) ΔS is positive and therefore, ΔH should be negative.
(d) ΔS is positive and therefore, ΔH should also be highly positive. 

Question. For the reaction, X₂O_4(l) 2XO_2(g) DU = 2.1 kcal, ΔS = 20 cal K–1 at 300 K Hence, ΔG is
(a) 2.7 kcal
(b) – 2.7 kcal
(c) 9.3 kcal
(d) – 9.3 kcal

Question. For the reaction, 2Cl_(g) → Cl_2(g), the correct option is
(a) ΔrH > 0 and ΔrS > 0
(b) ΔrH > 0 and ΔrS < 0
(c) ΔrH < 0 and ΔrS > 0
(d) ΔrH < 0 and ΔrS < 0

Question. In which case change in entropy is negative?
(a) 2H_(g) → H_2(g)
(b) Evaporation of water
(c) Expansion of a gas at constant temperature
(d) Sublimation of solid to gas 

Question. A reaction having equal energies of activation for forward and reverse reactions has
(a) ΔH = 0
(b) ΔH = DG = ΔS = 0
(c) ΔS = 0
(d) ΔG = 0 

Question. For vaporization of water at 1 atmospheric pressure, the values of ΔH and ΔS are 40.63 kJ mol^–1 and 108.8 J K^–1 mol^–1, respectively. The temperature when Gibbs’ energy change ΔG) for this transformation will be zero, is
(a) 273.4 K
(b) 393.4 K
(c) 373.4 K
(d) 293.4 K 

Question. The values of ΔH and ΔS for the reaction, C_(graphite) + CO_2(g) → 2CO_(g) are 170 kJ and 170 J K^–1, respectively. This reaction will be spontaneous at
(a) 910 K
(b) 1110 K
(c) 510 K
(d) 710 K

Question. The enthalpy of fusion of water is 1.435 kcal/mol. The molar entropy change for the melting of ice at 0°C is
(a) 10.52 cal/(mol K)
(b) 21.04 cal/(mol K)
(c) 5.260 cal/(mol K)
(d) 0.526 cal/(mol K)

Question. If the enthalpy change for the transition of liquid water to steam is 30 kJ mol^–1 at 27°C, the entropy change for the process would be
(a) 10 J mol^–1 K^–1
(b) 1.0 J mol^–1 K^–1
(c) 0.1 J mol^–1 K^–1
(d) 100 J mol^–1 K^–1

Question. Which of the following pairs of a chemical reaction is certain to result in a spontaneous reaction?
(a) Exothermic and increasing disorder
(b) Exothermic and decreasing disorder
(c) Endothermic and increasing disorder
(d) Endothermic and decreasing disorder 

Question. A reaction occurs spontaneously if
(a) TΔS < ΔH and both ΔH and ΔS are +ve
(b) TΔS > ΔH and DH is +ve and ΔS is –ve
(c) TΔS > ΔH and both ΔH and ΔS are +ve
(d) TΔS = ΔH and both ΔH and ΔS are +ve 

Question. Standard enthalpy and standard entropy changes for the oxidation of ammonia at 298 K are –382.64 kJ mol^–1 and –145.6 J mol^–1, respectively. Standard Gibbs’ energy change for he same reaction at 298 K is
(a) – 221.1 kJ mol^–1
(b) – 339.3 kJ mol^–1
(c) – 439.3 kJ mol^–1
(d) – 523.2 kJ mol^–1

Question. Identify the correct statement for change of Gibbs’ energy for a system (ΔG_system) at constant temperature and pressure.
(a) If ΔG_system < 0, the process is not spontaneous.
(b) If ΔG_system > 0, the process is spontaneous.
(c) If ΔG_system = 0, the system has attained equilibrium.
(d) If ΔG_system = 0, the system is still moving in a particular direction.

Question. The enthalpy and entropy change for the reaction: Br_2(l) + Cl_2(g) → 2BrCl_(g) are 30 kJ mol^–1 and 10⁵ J K^–1 mol^–1 respectively. The temperature at which the reaction will be in equilibrium is
(a) 300 K
(b) 285.7 K
(c) 273 K
(d) 450 K 

Question. Considering entropy (S) as a thermodynamic parameter, the criterion for the spontaneity of any process is
(a) ΔS_system + ΔS_surroundings > 0
(b) ΔS_system – ΔS_surroundings > 0
(c) ΔS_system > 0 only
(d) ΔS_surroundings > 0 only. 

Question. What is the entropy change (in J K^–1 mol^–1) when one mole of ice is converted into water at 0°C? (The enthalpy change for the conversion of ice to liquid water is 6.0 kJ mol^–1 at °C.)
(a) 20.13
(b) 2.013
(c) 2.198
(d) 21.98