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When a balloon is ruptured suddenly, or a tyre is punctured suddenly, the air inside the balloon/ tyre rushes out rapidly to the atmosphere. This process (expansion of air inside the balloon/tyre) is so quick that there is no time for transfer of heat from the system to the surroundings or from the surroundings to the system. Such an adiabatic expansion is called free expansion. It is characterized by Q = W = 0, implying ∆ U = 0. Free expansion is an uncontrolled change and the system is not in thermodynamic equilibrium. Free expansion cannot be illustrated with a P-V diagram as only the initial state and final state are known.

The critical temperature of water is 374.1°C.

Heat is a type of energy which travels from a hotter body to a cooler one.

Reversible Process :

1. The process is carried out infinitesimally slowly.
2. At any stage, the equilibrium is not disturbed.
3. It takes infinite time for completion.
4. Work obtained in this process is maximum.

Irreversible Process :

1. It is carried out rapidly.
2. Equilibrium may exist only after the completion of the process.
3. It takes a finite time for completion.
4. Work obtained in this process is not maximum.

The pressure cooker is based on the principle that the B.P. of water increase with increase in pressure.

Yes; according to Zeroth law of Thermodynamics.

Law of conservation of energy.

PV^γ = constant, where γ = \(\frac { { C }_{ p } }{ { C }_{ v } } \) which is known as atomicity of gas

In one complete cycle of refrigeration, the refrigerant, a liquid such as fluorinated hydrocarbon, goes through the following steps :

1. The refrigerant in the closed tube passes through the nozzle and expands, into a low-pressure area. This adiabatic expansion results in reduction in pressure and temperature of the fluid and the fluid turns into a gas

2. The cold gas is in thermal contact with the inner compartment of the fridge. Here it absorbs heat at constant pressure from the contents of the fridge.

3. The gas passes to a compressor where it does work in adiabatic compression. This raises its temperature and converts it back into a liquid. 

4. The hot liquid passes through the coils on the outside of the refrigerator and releases heat to the air outside in an isobaric compression process. The compressor, driven by an external source of energy, does work on the refrigerant during each cycle.

Refrigeration is artificial cooling of a space or substance of a system and/or maintaining its temperature below the ambient temperature.

Data : η = 25% = 0.25, Q_H = 50000 J W

η = \(\frac{W}{Q_H}\)

∴ W = _ηQ_H = (0.25)(50000)J = 12500J

Now, W = Q_H – |Q_C|

∴ |Q_C| = Q_H – W

= (50000 

– 12500) J = 37500J 

This is the heat rejected to the cold reservoir in one cycle. 

[Notes : Q_C = – 37500 J]

Standard enthalpy of formation of a compound is the change in enthalpy. when one mole of the compound is formed from its elements in their standard states under standard conditions i.e., at 298 K and 101.3 kPa pressure.

Correct answer is: (B) energy

1/2 N₂(g) + 1/2 O₂(g) → ANO(g)ΔH = +90.4kJ When 1 mole of nitric oxide is formed from its elements 90.4 kJ of heat is absorbed.

Gibb’s Helmholtz Equation can be given as :
∆G = ∆H – T∆S
Where; ∆G = Free energy change
∆H = Enthalpy change
∆S = Entropy change
T = Absolute temperature

Enthalpy of neutralization of ammonium hydroxide (weak base) and hydrochloric acid (strong acid) is -51.5 kJ.