Q. No.1. 0
2. –50 kJ
3. 50 kJ
4. –40 kJ
Five moles of an ideal gas at 1 bar and 298 K are expanded into a vacuum till the volume doubles. The work done is:
1. –RT ln V2/V1
2. CV(T2 – T1)
3. zero
4. – RT(V2 – V1)
Which one of the following equations does not correctly represent the first law of thermodynamics for the given processes involving an ideal gas? (Assume non-expansion work is zero)
1. Adiabatic process :
2. Cyclic process:
3. Isothermal process:
4. Isochoric process:
The change in internal energy, ∆U, in kJ, when a spring undergoes compression, with 10 kJ of work performed and 2 kJ escaping as heat to the surroundings is:
| 1. | 12 | 2. | –8 |
| 3. | 8 | 4. | –12 |
An ideal gas is allowed to expand form 1 L to 10 L against a constant external pressure of 1 bar. The work done in kJ is:
1. +10.0
2. – 9.0
3. – 2.0
4. –0.9
An ideal gas expands in volume from \(1×10^{–3} m^3\) to \(1×10^{–2} m^3\) at 300 K against a constant pressure of 1×105 Nm-2. The work done is:
| 1. | –900 J | 2. | –900 kJ |
| 3. | 270 kJ | 4. | 900 kJ |
| Column I | Column II | ||
| (i) | Spontaneous process | (a) | Isothermal and isobaric process |
| (ii) | \(\Delta H^\circ\) | (b) | \(\Delta H<0 \) |
| (iii) | \(\Delta T=0, \Delta P=0 \) | (c) | \(\Delta G<0 \) |
| (iv) | Exothermic process | (d) | (Bond energy of reactant) - (Bond energy of product) |
| I | II | III | IV | |
| 1. | c | d | a | b |
| 2. | b | a | c | d |
| 3. | d | b | c | d |
| 4. | a | d | b | c |
| Assertion (A): | The first law of thermodynamics has the equation: ∆U = q + W |
| Reason (R): | The first law of thermodynamics is based on the law of conservation of energy. |
| 1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
| 3. | (A) is True but (R) is False. |
| 4. | Both (A) and (R) are False. |
1. Increases
2. Remains constant
3. Decreases
4. Can be increased or decreased
| List I | List II | ||
| (A) | Adiabatic | (P) | ∆T = 0 |
| (B) | Isothermal | (Q) | Heat exchange is zero |
| (C) | Isochoric | (R) | ∆P = 0 |
| (D) | Isobaric | (S) | Work done is zero |
1. A → Q, B → P, C → S, D → R
2. A → P, B → Q, C → R, D → S
3. A → S, B → R, C → Q, D → P
4. A → P, B → R, C → S, D → Q
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