A gas expands slowly in a cylinder at a constant pressure of $2.40\times10^5\ \text{Pa}$. The piston has cross-sectional area $3.0\times10^{-3}\ \text{m}^2$ and moves outwards by $0.080\ \text{m}$.

A large block of ice melts reversibly at $0\ ^\circ\text{C}$. The ice absorbs $3.34\times10^5\ \text{J}$ of energy by heating while its temperature remains constant.

A proposed cyclic engine takes $500\ \text{J}$ from a single thermal reservoir in each cycle and delivers $500\ \text{J}$ of useful work, with no other energy transfer.

A rigid, insulated container is divided into two equal parts by a thin partition. One side contains an ideal gas and the other side is a vacuum. The partition is broken and the gas fills the whole container.

The diagram shows four possible processes for the same fixed mass of ideal gas starting at state A on a pressure-volume graph.

A fixed mass of ideal gas is taken from state A to state C by three different paths on a pressure-volume diagram. The gas is monatomic for all paths.

A gas initially occupies one side of an insulated rigid container. A valve is opened and the gas expands freely into the evacuated side. The container is treated as an isolated system.

A sample of $0.250\ \text{mol}$ of a monatomic ideal gas is heated from $290\ \text{K}$ to $350\ \text{K}$. During this process the gas does $95\ \text{J}$ of work on its surroundings.

Eight distinguishable particles are placed in a box divided into left and right halves. Each particle is equally likely to be in either half. A macrostate is described only by the number of particles in the left half.

Water in a freezer releases $6.0\times10^3\ \text{J}$ of energy as it freezes at $273\ \text{K}$. The freezer transfers this energy to the kitchen air at $300\ \text{K}$. Treat each energy transfer as occurring at constant temperature.

A heat engine uses a fixed mass of gas in a cyclic process. In each cycle the gas absorbs $1.80\ \text{kJ}$ from a hot reservoir and rejects $1.10\ \text{kJ}$ to a cold reservoir.

A proposed power station operates between a hot reservoir at $620\ \text{K}$ and a cold reservoir at $310\ \text{K}$. The designers claim that the thermal efficiency of the station will be $58\ \%$.

A fixed amount of gas is contained in a cylinder fitted with a frictionless movable piston. The gas is heated slowly so that it expands along the process shown.

Water in a shallow tray is placed in a freezer compartment. The water freezes while the freezer coils and the room act as the surroundings. The data refer to the freezing stage only, when the temperature of the water is constant.

A simple model represents six distinguishable gas particles as counters that can each be in the left or right half of a box. The macrostate is specified by the number of counters in the left half.

A fixed mass of gas undergoes a clockwise cyclic process ABCDA. The cycle consists of two constant-pressure processes and two constant-volume processes.

Three heat-engine cycles are tested using the same hot reservoir. The table gives the energy taken from the hot reservoir and the energy rejected to the cold reservoir during one cycle.

A monatomic ideal gas undergoes a rapid adiabatic compression. Initially $P_1=1.20\times10^5\ \text{Pa}$ and $V_1=4.00\times10^{-3}\ \text{m}^3$. The final volume is $2.00\times10^{-3}\ \text{m}^3$.

A sample of monatomic ideal gas is taken through a process in which the pressure changes approximately linearly with volume. The temperature of the gas is measured at the initial and final states.

Two large thermal reservoirs are connected by a device. In trial 1 the device operates as a passive conductor. In trial 2 the device is claimed to transfer energy from the cold reservoir to the hot reservoir without any external work input.

A monatomic ideal gas is compressed rapidly in a well-insulated cylinder. The pressure and volume at the start and end of the compression are shown.

Two proposed heat engines operate between thermal reservoirs. The table gives the reservoir temperatures and the measured efficiency for each engine.

A simple model represents eight distinguishable particles that can each occupy either the left half or the right half of a box. A macrostate is specified by the number of particles in the left half.

A sample of water of mass $0.120\ \text{kg}$ freezes at $273\ \text{K}$ in surroundings that remain at $268\ \text{K}$. The specific latent heat of fusion of water is $3.34\times 10^5\ \text{J kg}^{-1}$. Treat the freezing water and surroundings as the thermodynamic universe for this process.

Two identical rigid containers are connected by a valve. Initially, $0.020\ \text{mol}$ of monatomic ideal gas is in the left container and the right container is evacuated. The containers are thermally insulated from the surroundings. The valve is opened and the gas expands freely into the total volume.

A power station uses a thermal cycle to drive a generator. In one operating interval, $2.50\ \text{MJ}$ of energy is transferred from the hot source to the working substance and $0.80\ \text{MJ}$ of electrical energy is delivered to the grid. The highest working temperature is $820\ \text{K}$ and the cooling reservoir is at $295\ \text{K}$.

Two large bodies are placed in thermal contact inside an insulated container. During a short interval, $500\ \text{J}$ of energy is transferred by heating from the hotter body at $350\ \text{K}$ to the colder body at $300\ \text{K}$. The temperatures may be treated as constant during this interval.

A heat engine is modelled using a four-stage cycle for a monatomic ideal gas. The measured energy transfers and work for three stages are shown; the fourth stage returns the gas to its initial state.

A fixed amount of monatomic ideal gas is enclosed by a frictionless piston. The gas contains $0.075\ \text{mol}$. The gas expands from state A to state B along the path shown on the pressure-volume graph. During the expansion, $95\ \text{J}$ of energy is transferred to the gas by heating.

A monatomic ideal gas is compressed reversibly in a well-insulated cylinder. Initially the gas has pressure $1.10\times 10^5\ \text{Pa}$, volume $4.8\times 10^{-3}\ \text{m}^3$ and temperature $290\ \text{K}$. The final volume is $2.4\times 10^{-3}\ \text{m}^3$.

A monatomic ideal gas undergoes a clockwise rectangular cycle on a pressure-volume diagram. The upper pressure is $4.0\times 10^5\ \text{Pa}$, the lower pressure is $1.5\times 10^5\ \text{Pa}$, the smaller volume is $1.0\times 10^{-3}\ \text{m}^3$ and the larger volume is $3.0\times 10^{-3}\ \text{m}^3$. The energy transferred to the gas from the hot reservoir in one cycle is $650\ \text{J}$. The reservoirs are at $700\ \text{K}$ and $310\ \text{K}$.

An ideal Carnot engine operates between a hot reservoir at $750\ \text{K}$ and a cold reservoir at $310\ \text{K}$. In one cycle, $1.20\ \text{kJ}$ of energy is transferred from the hot reservoir to the engine.

A fixed mass of monatomic ideal gas expands along a straight-line path on a pressure-volume diagram. The pressure decreases from $4.2\times 10^5\ \text{Pa}$ to $2.2\times 10^5\ \text{Pa}$ while the volume increases from $1.0\times 10^{-4}\ \text{m}^3$ to $5.0\times 10^{-4}\ \text{m}^3$. During the process $230\ \text{J}$ of energy is transferred to the gas by heating. The amount of gas is $0.060\ \text{mol}$.

A fixed amount of monatomic ideal gas is taken around a cycle with states A, B and C. The coordinates are A: $V=2.0\times 10^{-3}\ \text{m}^3$, $P=3.0\times 10^5\ \text{Pa}$; B: $V=6.0\times 10^{-3}\ \text{m}^3$, $P=3.0\times 10^5\ \text{Pa}$; C: $V=6.0\times 10^{-3}\ \text{m}^3$, $P=1.0\times 10^5\ \text{Pa}$. The path from C to A is isothermal.

A refrigerator removes $180\ \text{J}$ of energy by heating from an interior at $260\ \text{K}$ and transfers energy to a room at $300\ \text{K}$ during one cycle. The refrigerator is powered by an external electrical supply.