THERMODYNAMICS Flashcards
What is thermodynamics?
Thermodynamics is the branch of physics that deals with the relationships between heat and other forms of energy.
State the first law of thermodynamics.
The first law of thermodynamics states that energy cannot be created or destroyed, only transformed from one form to another.
What is the formula for the first law of thermodynamics?
The formula is ΔU = Q - W, where ΔU is the change in internal energy, Q is the heat added to the system, and W is the work done by the system.
True or False: The internal energy of a system is dependent on its temperature.
True.
What is an isothermal process?
An isothermal process is a thermodynamic process that occurs at a constant temperature.
Define an adiabatic process.
An adiabatic process is one in which no heat is exchanged with the surroundings.
What is the significance of the second law of thermodynamics?
The second law of thermodynamics states that the total entropy of an isolated system can never decrease over time.
Fill in the blank: The unit of heat is _____
Joule.
What does the term ‘entropy’ refer to?
Entropy is a measure of the disorder or randomness in a system.
What is the principle of conservation of energy?
The principle of conservation of energy states that energy can neither be created nor destroyed, only transformed.
True or False: In a closed system, energy can be transferred but not created or destroyed.
True.
What is an isobaric process?
An isobaric process is a thermodynamic process that occurs at a constant pressure.
What does the term ‘enthalpy’ mean?
Enthalpy is a thermodynamic quantity that represents the total heat content of a system.
What is the equation for work done by a gas during expansion?
The work done by a gas is given by W = PΔV, where P is pressure and ΔV is the change in volume.
Define the term ‘heat capacity.’
Heat capacity is the amount of heat required to change the temperature of a substance by one degree Celsius.
What is the difference between specific heat and molar heat capacity?
Specific heat is the heat capacity per unit mass, while molar heat capacity is the heat capacity per mole of a substance.
Fill in the blank: The Kelvin scale is an absolute temperature scale where 0 K is known as _____.
absolute zero.
What are the three laws of thermodynamics?
The three laws are: 1) The first law (conservation of energy), 2) The second law (entropy), 3) The third law (absolute zero cannot be reached).
What is a heat engine?
A heat engine is a device that converts heat energy into mechanical work.
True or False: The efficiency of a heat engine is defined as the ratio of work output to heat input.
True.
What is the Carnot theorem?
The Carnot theorem states that no heat engine operating between two heat reservoirs can be more efficient than a Carnot engine.
What is the formula for the efficiency of a Carnot engine?
The efficiency (η) is given by η = 1 - (T_C / T_H), where T_C is the absolute temperature of the cold reservoir and T_H is the absolute temperature of the hot reservoir.
What does the term ‘thermal equilibrium’ mean?
Thermal equilibrium is the state in which two bodies in contact do not exchange heat, meaning they are at the same temperature.
What is the role of a refrigerator in thermodynamics?
A refrigerator transfers heat from a low-temperature reservoir to a high-temperature reservoir, using work input.
Fill in the blank: The efficiency of a real heat engine is always _____ than that of an ideal heat engine.
less.
Define ‘work’ in the context of thermodynamics.
In thermodynamics, work is the energy transferred when a force is applied over a distance.
What is the significance of absolute zero?
Absolute zero is the theoretical temperature at which a system has minimal energy, and it is the lowest limit of the thermodynamic temperature scale.
What is a thermodynamic cycle?
A thermodynamic cycle is a series of processes that return a system to its initial state.
True or False: In an isochoric process, the volume of the system remains constant.
True.
