In chemical reaction equations, chemical reaction equations that satisfy the law of conservation of mass are called chemical reaction metrological equations.

0=∑νB ×B

The stoichiometric number of reactants is negative, and the stoichiometric number of the product is positive.

ξ

mol

ξ=△nB/νB

definition

The reaction progress is related to the writing of the chemical reaction metrological equation. Therefore, when applying the physical quantity of reaction progress, the specific chemical reaction equation must be specified.

Separate some objects from other surrounding objects as a study The objects divided into this part become a system. (formerly known as system)

Classification basis

category

The parts outside the system that are closely related to the system are called the environment.

The state of the system is a comprehensive manifestation of all macro properties and macro physical quantities of the system.

These macro-physical quantities that determine the existence status of the system It is called the state function of the system.

The change value of the state function depends only on the beginning and end states of the system. It has nothing to do with the path of system change.

Classification basis

Nature Category

The status is certain, the value is certain, the difference in the same destination, etc.

The various state functions of the system are mutually restricted: p, V, T, n

The set of state functions is also a state function

When the state of the system changes, this change is called a process.

Isothermal process

Isopressure process

Isovolume process

Specific steps to complete this change

The form of energy exchange between the system and the environment due to temperature differences.

Q

Various forms of energy exchange between the system and the environment, except heat, are collectively called work.

W

Volume work (expansion work)

Non-volume work (useful work)

It is between the system state and the environment when it changes Two forms of energy exchange.

J or KJ

Neither heat nor work are the state functions of the system. In addition to being related to the beginning and end states of the system It is also related to the specific ways of system state changes.

It is the sum of various forms of energy within the system.

U

It is the state function of the system.

The internal kinetic energy of molecules in the system, intermolecular interaction energy, Inside the molecule

Because the movement and interaction of particles inside the system are very complex, they can only measure their changes

It is only related to the beginning and end states, but not to the specific path of the process.

In isolation systems, the forms of energy can be converted to each other, but the total value of energy remains unchanged.

△U＝Q＋W