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Class 11 Thermodynamics worksheet
CBSE Chemistry. First law, ΔH and ΔU, Hess’s law, bond enthalpies, entropy and Gibbs energy. Every sheet has 20 questions in three sections and an answer key, and the numbers change every time.
Sample questions
Real questions from this chapter, as the app sets them. Tap Answer to see the answer and working.
Section A · multiple choice
- 1.
A system that can exchange energy but not matter with its surroundings is:
- an isolated system
- an adiabatic system
- an open system
- a closed system
Answer
(d) a closed system
- 2.
For the reaction CaCO₃(s) → CaO(s) + CO₂(g), Δn_g (the change in moles of gas) is:
- +1
- +2
- +3
- 0
Answer
(a) +1
moles of gaseous products − moles of gaseous reactants; ignore solids and liquids
- 3.
A gas expands from 1 L to 20 L against a constant external pressure of 2 bar. The work done on the gas is: (1 L bar = 100 J)
- −38 J
- 3,800 J
- −38,000 J
- −3,800 J
Answer
(d) −3,800 J
w = −p_ext ΔV = −2 × (20 − 1) L bar
Section B · short answer
- 4.
Distinguish between a state function and a path function, with one example of each.
Answer
A state function depends only on the initial and final states of the system, not on how the change happens (internal energy, enthalpy, entropy). A path function depends on the route taken (heat, work).
- 5.
For 2CO(g) + O₂(g) → 2CO₂(g), ΔH = −566 kJ at 400 K. Find ΔU. (R = 8.314 J/K mol) (2 decimal places where needed.)
Answer
−562.67 kJ
ΔU = ΔH − Δn_g RT = −566 − (−1 × 8.314 × 400 ÷ 1000)
Section C · long answer
- 6.
Explain the terms system, surroundings and boundary, and the three types of system, with examples.
Answer
The system is the part of the universe being studied; the surroundings are everything else; the boundary separates them. Open system: exchanges energy and matter (an open beaker of hot water). Closed system: exchanges energy but not matter (a sealed flask). Isolated system: exchanges neither (water in a perfect thermos flask).
Fresh sheets for your child
In the app, every Thermodynamics sheet is new: the app remembers the questions your child has already had and leaves them out. Print the sheet as a PDF, or use notebook mode and write the answers in a notebook.
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