How is the standard state of a gas defined?

The standard state of a gas is an imaginary state, defined as an ideal gas state equation at a standard pressure (105 pa, or 1 bar).

of pure gases. Although no single real gas has a completely ideal behavior, this definition of a standard state allows for the correction of the non-ideality of different gases.

Because most gases are difficult to observe directly, they are often described by their four physical or macroscopic properties: pressure, volume, number of particles (expressed by chemists in moles), and temperature.

These four attributes have been used by many scientists (e.g. Robert Boyle, Jacques Charlie, John Dalton.

Joseph Louis Gay-Lussac, Amodeo Avogadro.

etc.) have been repeatedly observed through different gases and different devices. Their careful study culminated in the ideal gas laws that describe the mathematical relationships of these properties.

The total pressure is different from the partial pressure, when you think of the gas as the total volume, and when the gas occupies the volume according to the amount of different substances, it is the total pressure, when you calculate the enthalpy change, you naturally imagine the gas as the volume, so the total pressure is the standard pressure.

The standard condition is that the temperature of the gas is 0 degrees Celsius (, and the pressure is.

The status of the PA. In this state, the molar volume of the gas is, of course, it is accurate to say that the molar volume of different gases under standard conditions is not the same.

Substances that are not gaseous under standard conditions include SO3, H O, HF, alcohol, and benzene.

Sulfur trioxide is a colorless and easily sublimated solid with three phases. (High school chemistry generally thinks that it is a liquid under normal conditions, a solid under standard conditions, and a gas when heated.) ）

SO3 filamentous fibrous and needle-like, density, melting point; SO3 asbestos fibrous, melting point, sublimation at 50; SO3 glassy, melting point, boiling point. It dissolves in water and reacts with water to form sulfuric acid and release a large amount of heat.

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Temperature. There are three standard states of gas:

The standard status of the 10th International Conference on Weights and Measures (CGPM) protocol is: temperature, pressure. This standard is widely used in the scientific and technological fields of countries around the world.

2. The International Organization for Standardization and the American National Standard stipulate that temperature and pressure are used as the standard state for measuring the volume flow rate of gases.

3. China's "Standard Orifice Plate Calculation Method for Natural Gas Flow" stipulates that temperature and pressure are used as the standard state for measuring gas volume flow.

The standard state of high school physical gas is 1atm, 0.

The standard state of the gas refers to the standard orifice plate calculation method of the natural gas flow rate of the system at a certain open burial temperature.

There are three standard states of gas:

The standard state agreed by the 10th International Conference on Weights and Measures in 1954 is: temperature 0 degrees Celsius, pressure kPa. This stool is widely used in the scientific and technological fields of countries around the world.

The International Organization for Standardization (ISO) and the American National Standard stipulate that a temperature of 15 degrees Celsius and a pressure of kilopascals are used as the standard state for measuring the volume flow rate of gases. China's "Standard Orifice Plate Calculation Method for Natural Gas Flow" stipulates that the temperature of 20 degrees Celsius and the pressure of kilopascals are used as the standard state for measuring the volume flow rate of gas.

There are three standard states of gas:

The standard state of the 10th International Conference on Weights and Measures (CGPM) is: temperature, pressure. This standard state is widely used in the scientific and technological fields of countries around the world.

2. The International Organization for Standardization and the American National Standard stipulate that temperature and pressure are used as the standard state for measuring the volume flow rate of gases.

3. China's "Standard Orifice Plate Calculation Method for Natural Gas Flow" stipulates that temperature and pressure are used as the standard state for measuring gas volume flow.

The standard state of a gas is the state at which the temperature is and the standard atmospheric pressure. The following is an analysis of the standard state of the gas from three aspects.

1.Temperature.

In general, the state parameters of a gas are pressure, temperature, and volume. In the standard state of a gas, the temperature is a fixed value, ie. This temperature is the historical reason for the choice, which originated in the first half of the 19th century, when scientists discovered that gases could be clustered like sails at 0 when studying their properties.

Later, the standard temperature of the gas was established internationally.

2.Stress

In the standard state, the pressure of the gas is defined as the standard atmospheric pressure, ie. This value is the average value of atmospheric pressure at sea level, which is equivalent to 760 mm Hg.

3.Applications

The standard state of gases is widely used in chemistry, physics, engineering, and other fields. In chemical reactions, it is often necessary to convert the actual state of the gas into a standard state of hail for easy calculation and comparison; In physics, standard states are often used to describe the properties and properties of gaseous matter; In engineering, standard states are also used to establish a baseline for gas measuring instruments.

In summary, the standard state of a gas refers to the state of the gas at a temperature and standard atmospheric pressure. This definition is accurate and simple, and facilitates research and application in many fields.