GkSeries.com

MCQ on Class 11 Chemistry Chapter 6 Thermodynamics for NEET

(1) The standard enthalpy of formation (ΔfH°) at 298 K for methane, CH4(g), is –74.8 kJ mol–1. The additional information required to determine the average energy for C – H bond formation would be
[A] the dissociation energy of H2 and enthalpy of sublimation of carbon
[B] latent heat of vaporization of methane
[C] the first four ionization energies of carbon and electron gain enthalpy of hydrogen
[D] the dissociation energy of hydrogen molecule, H2
Answer: the dissociation energy of H2 and enthalpy of sublimation of carbon
(2) An ideal gas is allowed to expand both reversibly and irreversibly in an isolated system. If Ti is the initial temperature and Tf is the final temperature, which of the following statements is correct?
[A] (Tf)irrev > (Tf)rev
[B] Tf > Ti for reversible process but Tf = Ti for irreversible process
[C] (Tf)rev = (Tf)irrev
[D] Tf = Ti for both reversible and irreversible processes
Answer: (Tf)irrev > (Tf)rev

DOWNLOAD CURRENT AFFAIRS PDF FROM APP

(3) Which of the following is an intensive property?
[A] temperature
[B] surface tension
[C] viscosity
[D] all of these
Answer: all of these
(4) If one mole of ammonia and one mole of hydrogen chloride are mixed in a closed container to form ammonium chloride gas, then
[A] ΔH > Δu
[B] ΔH = Δu
[C] ΔH < Δu
[D] there is no relationship
Answer: ΔH < Δu
(5) In a constant volume calorimeter, 3.5 g of a gas with molecular weight 28 was burnt in excess oxygen at 298.0 K. The temperature of the calorimeter was found to increase from 298.0 K to 298.45 K due to the combustion process. Given that the heat capacity of the calorimeter is 2.5 kJ K−1, the numerical value for the enthalpy of combustion of the gas in kJ mol−1 is
[A] 3
[B] 7
[C] 8
[D] 9
Answer: 9
(6) The amount of heat evolved when 500 cm3 of 0.1 M HCl is mixed with 200 cm3 of 0.2 M NaOH is ______.
[A] 1.292 kJ
[B] 2.292 kJ
[C] 3.392 kJ
[D] 0.292 kJ
Answer: 2.292 kJ
(7) The standard enthalpy of formation of NH3 is –46.0 kJ mol–1. If the enthalpy of formation of H2 from its atoms is –436 kJ mol–1 and that of N2 is –712 kJ mol–1, the average bond enthalpy of N — H bond is NH3 is
[A] –1102 kJ mol–1
[B] –964 kJ mol–1
[C] +352 kJ mol–1
[D] +1056 kJ mol–1
Answer: +352 kJ mol–1
(8) The species which by definition has ZERO standard molar enthalpy of formation at 298 K is
[A] Br2(g)
[B] Cl2(g)
[C] H2O(g)
[D] CH4(g)
Answer: Cl2(g)
(9) The bond energy (in kcal mol–1) of a C—C single bond is approximately
[A] 1
[B] 10
[C] 100
[D] 1000
Answer: 100
(10) The amount of the heat released when 20 ml 0.5 M NaOH is mixed with 100 ml 0.1 M HCl is x kJ. The heat of neutralization is
[A] – 100 x kJ/mol
[B] – 50 x kJ/mol
[C] + 100 x kJ/mol
[D] +50 x kJ/mol
Answer: – 100 x kJ/mol
(11) Based on the first law of thermodynamics, which one of the following is correct? [Karnataka CET 2011]
[A] For an isothermal process, q = +w
[B] For an isochoric process, ΔU = -q
[C] For an adiabatic process, ΔU = -w
[D] For a cyclic process, q = -w
Answer: For a cyclic process, q = -w
(12) Consider the reaction :

4NO2(g) + O2(g) ® 2N2O5(g), ΔrH = –111kJ.

If N2O5(s) is formed instead of N2O5(g) in the above reaction, the ΔrH value will be:

(given, ΔH of sublimation for N2O5 is 54 kJ mol–1)

[A] –219 kJ
[B] –165 kJ
[C] + 54 kJ
[D] + 219 kJ
Answer: –219 kJ
(13) 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] 5.260 cal/(mol K)
[B] 0.526 cal/(mol K)
[C] 10.52 cal/(mol K)
[D] 21.04 cal/(mol K)
Answer: 5.260 cal/(mol K)
(14) Standard enthalpy of vapourisation DvapHQ for water at 100° C is 40.66 kJmol–1. The internal energy of vapourisation of water at 100°C (in kJmol–1) is
[A] +43.76
[B] +40.66
[C] +37.56
[D] –43.76
Answer: +37.56
(15) Choose the correct answer. A thermodynamic state function is a quantity
[A] used to determine heat changes
[B] whose value is independent of path
[C] used to determine pressure volume work
[D] whose value depends on temperature only.
Answer: whose value is independent of path
(16) For the process to occur under adiabatic conditions, the correct condition is
[A] ΔT = 0
[B] Δp = 0
[C] g = 0
[D] w=0
Answer: g = 0
(17) The enthalpies of all elements in their standard states are
[A] unity
[B] zero
[C] <0
[D] different for each element.
Answer: zero
(18) ΔU° of combustion of methane is – X kJ mol-1. The value of ΔH° is
[A] = ΔU°
[B] >ΔU°
[C] <ΔU°
[D] =0
Answer: <ΔU°
(19) The enthalpy of combustion of methane, graphite and dihydrogen at 298 K are, -890.3 kJ mol-1,-393.5 kJ mol-1 and-285.8 kJ mol-1 respectively. Enthalpy of formation of CH4(g) will be
[A] -74.8 kJ mol-1
[B] -52.27 kJ mol-1
[C] +74.8 kJ mol-1
[D] +52.26 kJ mol-1
Answer: -74.8 kJ mol-1
(20) A reaction, A + B → C + D + q is found to have a positive entropy change. The reaction will be
[A] possible at high temperature
[B] possible only at low temperature
[C] not possible at any temperature
[D] possible at any temperature
Answer: possible at any temperature

Please share this page

Chapters

Click Here to Read more questions

Teacher Eligibility Test