Thermo2 - Laws of Thermodynamics

What does the first law of thermodynamics state?

• Energy can be created and destroyed

• Energy cannot be created or destroyed, only transformed

• Energy can be created but not destroyed

• Energy is always conserved in isolated systems

Which equation represents the first law of thermodynamics?

• ΔU=Q+W

• ΔU=Q−W

• ΔU=W−Q

• ΔU=Q×W

Which of the following is an example of a process that obeys the first law of thermodynamics?

• Perpetual motion machines

• Conservation of mass

• A closed system where heat added equals the work done by the system plus change in internal energy

• An isolated system where heat is continuously produced without work

The second law of thermodynamics states that:

• Total energy is conserved in a system

• Entropy of an isolated system always decreases

• Entropy of an isolated system never decreases

• Energy can neither be created nor destroyed

In an adiabatic process:

• Heat is transferred to the surroundings

• No heat is transferred to or from the system

• Work is done on the system without changing its internal energy

• Temperature remains constant

What is the symbol for internal energy?

• Q

• W

• U

• H

In the first law of thermodynamics, what does WWW represent?

• Work done by the system

• Work done on the system

• Heat absorbed by the system

• Heat released by the system

The efficiency of a Carnot engine is determined by:

• The difference in volume of the gas

• The temperatures of the heat reservoirs

• The type of gas used

• The amount of work done

Which of the following is true for an isothermal process?

• Temperature remains constant

• Pressure remains constant

• Volume remains constant

• Entropy remains constant

Entropy can be best described as:

• The total energy of a system

• A measure of disorder or randomness

• The amount of work done by a system

• The heat transferred in a process