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Explore Chapter 6, Thermodynamics, with these Class 11 Chemistry MCQs, complete with answers. Designed in alignment with the CBSE curriculum and the latest syllabus for Class 11 Chemistry, these multiple-choice questions offer an excellent way for students to revise key concepts from the chapter. Practicing these MCQs will help students reinforce their understanding and prepare effectively for Class 11 annual exams, as well as competitive exams like NEET and JEE
Class 11 Thermodynamics MCQs – Question with Answers
- Which of the following is a state function?
a) Heat
b) Work
c) Internal Energy
d) DistanceAnswer: c) Internal Energy - The SI unit of energy is:
a) Joule
b) Calorie
c) Electron Volt
d) ErgAnswer: a) Joule - The first law of thermodynamics states:
a) Energy can be created.
b) Energy can neither be created nor destroyed.
c) Heat flows from cold to hot.
d) Entropy decreases in a system.Answer: b) Energy can neither be created nor destroyed. - If a system absorbs heat, the process is called:
a) Exothermic
b) Endothermic
c) Isothermal
d) AdiabaticAnswer: b) Endothermic - In an isothermal process, the temperature of the system:
a) Increases
b) Decreases
c) Remains constant
d) Changes continuouslyAnswer: c) Remains constant - Which process occurs at constant pressure?
a) Isochoric
b) Isobaric
c) Isothermal
d) AdiabaticAnswer: b) Isobaric - The term “q” in thermodynamics refers to:
a) Work
b) Heat
c) Energy
d) EnthalpyAnswer: b) Heat - Enthalpy (H) is equal to:
a) U + PV
b) U – PV
c) PV – U
d) PV / UAnswer: a) U + PV - In an adiabatic process:
a) No heat is transferred.
b) Pressure remains constant.
c) Volume remains constant.
d) Temperature remains constant.Answer: a) No heat is transferred. - For an ideal gas, work done in an isothermal expansion is given by:
a) nRT ln(V2/V1)
b) PΔV
c) CpΔT
d) CvΔTAnswer: a) nRT ln(V2/V1) - Entropy is a measure of:
a) Energy
b) Work
c) Disorder
d) PressureAnswer: c) Disorder - Which of the following statements is true about heat engines?
a) They convert all heat energy into work.
b) They violate the second law of thermodynamics.
c) Efficiency is less than 100%.
d) They are perpetual motion machines.Answer: c) Efficiency is less than 100%. - The second law of thermodynamics states that:
a) Heat flows from cold to hot naturally.
b) The entropy of the universe always increases.
c) Work can be done without energy input.
d) Energy is created during a chemical reaction.Answer: b) The entropy of the universe always increases. - If ΔH > 0 for a reaction, the reaction is:
a) Exothermic
b) Endothermic
c) Adiabatic
d) IsobaricAnswer: b) Endothermic - The standard enthalpy of formation of an element in its most stable form is:
a) Always positive
b) Always negative
c) Zero
d) UndefinedAnswer: c) Zero - Which formula is used to calculate the internal energy change (ΔU)?
a) ΔU = q – w
b) ΔU = q + w
c) ΔU = w – q
d) ΔU = PVAnswer: b) ΔU = q + w - The work done during the expansion of a gas is maximum in:
a) Adiabatic process
b) Isothermal process
c) Isochoric process
d) Free expansionAnswer: b) Isothermal process - Which of the following is NOT a thermodynamic process?
a) Isothermal
b) Isobaric
c) Isovolumetric
d) PhotochemicalAnswer: d) Photochemical - In an isochoric process, the work done is:
a) Zero
b) Positive
c) Negative
d) Cannot be determinedAnswer: a) Zero - Gibbs free energy change (ΔG) determines:
a) Heat transferred
b) Spontaneity of a process
c) Work done
d) Pressure changeAnswer: b) Spontaneity of a process - Which of the following represents the relationship between enthalpy (H), internal energy (U), and pressure-volume work (PΔV)?
a) H = U + PΔV
b) H = U – PΔV
c) H = PΔV – U
d) H = PΔV / UAnswer: a) H = U + PΔV - In which type of process is ΔU = 0?
a) Adiabatic process
b) Isochoric process
c) Isothermal process
d) Isobaric processAnswer: c) Isothermal process - The efficiency of a Carnot engine depends on:
a) The work done only
b) The heat supplied only
c) The temperature of the source and sink
d) The pressure differenceAnswer: c) The temperature of the source and sink - The heat change at constant pressure is equal to:
a) Internal energy change
b) Work done
c) Enthalpy change
d) Entropy changeAnswer: c) Enthalpy change - The spontaneous process has:
a) Positive ΔG
b) Negative ΔG
c) ΔG = 0
d) None of the aboveAnswer: b) Negative ΔG - Which statement is true for an exothermic reaction?
a) Heat is absorbed by the system.
b) Enthalpy of products is higher than reactants.
c) Heat is released to the surroundings.
d) The temperature of the system decreases.Answer: c) Heat is released to the surroundings. - The entropy change (ΔS) is positive when:
a) A liquid freezes into a solid
b) A gas condenses into a liquid
c) A solid melts into a liquid
d) The temperature decreasesAnswer: c) A solid melts into a liquid - The heat required to raise the temperature of 1 gram of a substance by 1°C is called:
a) Molar heat capacity
b) Specific heat capacity
c) Enthalpy
d) Latent heatAnswer: b) Specific heat capacity - What happens in an adiabatic expansion of an ideal gas?
a) Temperature increases
b) Temperature decreases
c) Pressure remains constant
d) Heat is absorbedAnswer: b) Temperature decreases - What is the value of work done in a free expansion of a gas?
a) Positive
b) Negative
c) Zero
d) Equal to heat absorbedAnswer: c) Zero
FAQs on Class 11 Chemistry Chapter 6 Thermodynamics
Is thermodynamics Class 11 tough?
Thermodynamics in Class 11 can feel challenging initially because it involves concepts like energy, heat, work, and their relationships, along with numerical problems. However, with a clear understanding of the basic principles and consistent practice of numerical problems and derivations, it becomes manageable and even enjoyable. Breaking down the concepts and practicing MCQs can make it easier.
Is thermodynamics chemistry important for NEET?
Yes, thermodynamics is a highly important topic for NEET. Questions from this chapter frequently appear in the NEET exam, as it forms the foundation for understanding energy changes in chemical reactions. Topics like enthalpy, entropy, Gibbs free energy, and the laws of thermodynamics are commonly tested. A strong grasp of these concepts is essential to score well in chemistry.
What is the first law of thermodynamics MCQ?
An example of a first-law MCQ could be: The first law of thermodynamics states that: a) Energy can be created. b) Energy can neither be created nor destroyed. c) Heat flows from cold to hot. d) Entropy decreases in a system. Answer: b) Energy can neither be created nor destroyed. This law is mathematically expressed as: ΔU = q + w, where ΔU is the change in internal energy, q is heat, and w is work done.
Is thermodynamics hard in Class 11 chemistry?
Thermodynamics in Class 11 Chemistry is not inherently hard but requires conceptual clarity and attention to detail. Students often find it tricky because of the combination of theory and numerical problems. However, focusing on understanding the laws, key formulas, and solving practice questions step by step makes it much more approachable.
What are the important topics of thermodynamics in Chemistry Class 11?
The important topics in thermodynamics for Class 11 Chemistry include:
1. Basic concepts: System, surroundings, types of systems, and processes (isothermal, adiabatic, isobaric, etc.).
2. First Law of Thermodynamics: Internal energy, enthalpy, and work done.
3. Second Law of Thermodynamics: Entropy and its significance.
4. Gibbs Free Energy: Relation to spontaneity of reactions.
5. Enthalpy changes: Heat of reaction, fusion, vaporization, and combustion.
6. Numerical problems: Based on laws of thermodynamics, enthalpy, and work done.
