Thermodynamics Flashcards
What is the first law of thermodynamics?
Energy cannot be created or destroyed, only transformed.
True or False: The second law of thermodynamics states that entropy in a closed system can decrease over time.
False
Fill in the blank: The measure of disorder or randomness in a system is known as ______.
entropy
What is the definition of thermodynamic equilibrium?
A state where macroscopic properties are uniform and do not change over time.
What does the term ‘enthalpy’ refer to?
The total heat content of a system, equal to the internal energy plus the product of pressure and volume.
Which law of thermodynamics introduces the concept of absolute zero?
The third law of thermodynamics.
True or False: A heat engine converts thermal energy into mechanical work.
True
What is the Carnot efficiency formula?
Efficiency = 1 - (T_c / T_h), where T_c is the cold reservoir temperature and T_h is the hot reservoir temperature.
What is a reversible process in thermodynamics?
A process that can be reversed without leaving any change in the system and surroundings.
Fill in the blank: The unit of temperature in the SI system is ______.
Kelvin
What is a state function?
A property whose value does not depend on the path taken to reach that specific value.
What is the significance of the Gibbs free energy?
It determines the spontaneity of a process at constant temperature and pressure.
True or False: In an isothermal process, the temperature remains constant.
True
What is the difference between an open system and a closed system?
An open system can exchange both matter and energy with its surroundings, while a closed system can exchange only energy.
What is specific heat capacity?
The amount of heat required to raise the temperature of one unit mass of a substance by one degree Celsius.
Fill in the blank: The process of heat transfer through direct contact is known as ______.
conduction
What is the equation for calculating work done by a gas during expansion?
W = PΔV, where P is pressure and ΔV is the change in volume.
What does the term ‘adiabatic process’ mean?
A process in which no heat is transferred to or from the system.
What is the latent heat of vaporization?
The amount of heat required to convert a unit mass of a substance from liquid to vapor at constant temperature.
True or False: Heat always flows from a colder object to a hotter object.
False
What is the difference between an ideal gas and a real gas?
An ideal gas follows the ideal gas law perfectly, while a real gas exhibits interactions between molecules and does not always follow the law.
Fill in the blank: The heat required to change a solid into a liquid at its melting point is called ______.
latent heat of fusion
What is the Clausius-Clapeyron equation used for?
It describes the relationship between pressure and temperature during phase changes.
What is the definition of a thermodynamic cycle?
A series of processes that return a system to its initial state.
True or False: The Zeroth law of thermodynamics states that if two systems are in thermal equilibrium with a third system, they are in thermal equilibrium with each other.
True
What is the purpose of a heat pump?
To transfer heat from a colder area to a hotter area using work.
What does ‘thermal conductivity’ refer to?
The ability of a material to conduct heat.
Fill in the blank: The temperature at which a substance changes from solid to liquid is called the ______.
melting point
What is a polytropic process?
A thermodynamic process that follows the relation PV^n = constant, where n is a constant.
What is the law of conservation of energy?
Energy cannot be created or destroyed, only transformed from one form to another.
True or False: In an isochoric process, the volume remains constant.
True
What is the definition of work in thermodynamics?
The energy transfer that occurs when a force is applied to move an object.
Fill in the blank: The process of heat transfer due to the movement of fluids is known as ______.
convection
What does the term ‘thermal equilibrium’ mean?
A condition where two objects in contact no longer transfer heat between them.
What is the ideal gas law?
PV = nRT, where P is pressure, V is volume, n is the number of moles, R is the universal gas constant, and T is temperature.
True or False: The change in internal energy of a system is equal to the heat added to the system minus the work done by the system.
True
What is the significance of the Helmholtz free energy?
It is used to determine the work obtainable from a closed system at constant volume and temperature.
Fill in the blank: The change in temperature required to produce a change in the state of a substance is referred to as ______.
phase transition
What is a heat exchanger?
A device that transfers heat between two or more fluids without mixing them.
What is the main principle behind refrigeration?
Removing heat from a designated area to lower its temperature.
True or False: Specific heat capacity is the same for all substances.
False
What is the concept of ‘thermal expansion’?
The increase in volume of a substance due to an increase in temperature.
Fill in the blank: The change of a substance from gas to liquid is called ______.
condensation
What does the term ‘non-equilibrium thermodynamics’ refer to?
The study of systems that are not in thermodynamic equilibrium.
