Thermodynamics

A system is the part

A system is the part of the universe where observations are made. Everything else is the surroundings. The boundary is the real or imaginary wall that

An open system exchanges both matter

An open system exchanges both matter and energy with the surroundings. A closed system exchanges energy but not matter. An isolated system exchanges n

Internal energy U is the total

Internal energy U is the total energy of the system, including chemical, electrical, mechanical, and other forms. It is a state function, so its chang

The first law is the law

The first law is the law of conservation of energy and is written as ΔU = q + w. Heat and work are path functions, but their sum gives the change in i

For expansion or compression against constant

For expansion or compression against constant external pressure, w = -p_ex(V_f - V_i). For reversible change, w_rev = -∫ p_ex dV. For reversible isoth