Thermochemistry MCQs for MDCAT Practice

Chemistry section, Thermochemistry chapter. Sample questions from past PMC papers.

1. Question 1
   Specific heat capacity of a substance X is 4J g−1K−1, its molar mass is 30g/mol. What is its molar heat capacity?
   • A.120 Jmol−1K−1
   • B.12 Jmol−1K−1
   • C.4 Jmol−1K−1
   • D.0.133 Jmol⁻¹K⁻¹
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2. Question 2
   If only the transfer of energy with the surrounding but not matter is possible, it is known as:
   • A.Open system
   • B.Closed system
   • C.Isolated system
   • D.Heterogeneous system
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3. Question 3
   The equation qr = ΔH represents:
   • A.Heat changes at constant pressure.
   • B.Enthalpy.
   • C.Pressure changes at normal pressure.
   • D.None of the above.
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4. Question 4
   Which of the following is exothermic reaction?
   • A.CH4 + 2O2 → CO2 + 2H2O
   • B.C+2S → CS2
   • C.H2 + I2 → 2HI
   • D.None of the above
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5. Question 5
   In thermochemistry, a liquid whose boiling point is to be determined is considered as a/an
   • A.final state
   • B.initial state
   • C.surrounding
   • D.system
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6. Question 6
   For an exothermic reaction, the energy level of reactant is
   • A.Less than the product
   • B.More than the product
   • C.Equal to the product
   • D.Zero
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7. Question 7
   CH4 + 2O2 → CO2 + 2H2O. What is the heat of formation of CH4 given:∆Hc (CH4) = -890, ∆Hf (CO2) = -393.5, ∆Hf (H2O) = -285.8?
   • A.-76
   • B.210
   • C.-210
   • D.76
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8. Question 8
   Internal energy of a system depends on all the factors EXCEPT:
   • A.Chemical nature of a substance
   • B.Temperature
   • C.Pressure and volume
   • D.Path
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