The principle of the fountain experiment, what is the principle of the fountain experiment?

The basic principle of the fountain experiment is the solubility of a gas in a liquid.

Large, in a short period of time to generate enough pressure difference (negative pressure), then open the piston after atmospheric pressure.

The liquid inside the beaker is pressed into the flask, creating a fountain at the mouth of the needle-nose catheter. To solve this problem, we think of several factors that affect air pressure. According to the Kraberon equation.

pv=nrt, launch p=(nrt) v

r is constant). To make p smaller, you can change one of the variables n, t, v. So there are three ways to reduce the air pressure: Reduce the amount of gas in the substance.

n)；reduce the temperature of the gas (t); Increase the volume of the gas (v). There are two ways to reduce the amount of gas in a substance: physical and chemical. The gas can be pumped away or dissolved by physical methods, and the chemical method can be chemically reacted.

or chemical dissolution; To reduce the temperature of the gas, we can use cold water or put a wet towel on the bottom of the bottle, or we can transfer the device to a lower temperature environment; The volume of the gas can be increased by increasing the temperature (e.g., pouring hot water or placing a hot towel at the bottom of the bottle) or changing the volume of the container.

The method of reducing the amount of gas substances by chemical methods is related to the solubility of the gas and the type of absorbent liquid. Gas solubility.

The size will have an impact on the formation of the fountain. For example, gases that are easily soluble in water, gases that are not soluble in water, and gases that are insoluble in water; Since their solubility in water is not the same, the pressure reduction is different, which is the key to whether the fountain can be produced and the size of the fountain. The type of absorbent will also have an impact on the formation of the fountain, and whether different absorbent fluids can react with the gas and the solubility of the gas in it all determine the success or failure of the fountain experiment.

By analyzing the principles and conditions of the fountain experiment, we concluded that the key to the success of the fountain experiment was: the flask containing the gas must be dry, otherwise there will be liquid in the flask, which will leave air at the mouth of the bottle, and the fountain pressure formed is not large (the fountain is "weak"); The flask should be filled with gas; The flask must not leak air (the airtightness of the device should be checked before the experiment); The gas used can be dissolved in large quantities in the liquid used or the gas reacts quickly with the liquid.

The principle of the fountain experiment is the Claberon equation.

The fountain experiment is a demonstration experiment in middle school chemistry teaching, and the first year chemistry textbook arranges a fountain experiment when talking about the properties of ammonia.

Due to the interesting and intuitive effect of the fountain experiment, it has now evolved into a series of fountain experiments beyond the scope of fountain experiments arranged in the textbook.

Description: The solubility of the gas in the liquid is very large, and a sufficient pressure difference (negative pressure) is generated in a short period of time, then after the piston is opened, the atmospheric pressure presses the liquid in the beaker into the flask, forming a fountain at the mouth of the needle-nose conduit.

By analyzing the principles and conditions of the fountain experiment, we conclude that the key to the success of the fountain experiment is:

1) The flask containing the gas must be dry, otherwise there is liquid in the flask, which will leave air at the mouth of the bottle, and the fountain formed will not have much pressure (the fountain is "weak").

2) The gas should fill the flask;

3) The flask should not leak air (the airtightness of the device should be checked before the experiment).

4) The gas used can be dissolved in a large amount of the liquid used or the gas reacts quickly with the liquid.

The above content refers to the Encyclopedia Fountain Experiment.

Mechanism of generation. According to the Claberon equation (also known as the ideal gas equation of state) :p v=nrt, p=(nrt) v (r is a constant) is introduced.

To make p smaller, you can change one of the variables n, t, v.

So there are three ways to reduce air pressure:

1. Reduce the amount of gaseous substances (n);

2. Reduce the temperature of the gas (t);

3. Increase the volume of gas (v).

There are two ways to reduce the amount of gas in a substance: physical and chemical.

A combination of fountains is formed1) NH3, HCl, SO2, NO2 can be combined with water to form a fountain.

2) The combination of acid gas and NaOH (AQ) can form a fountain.

3) The combination of organic gases and organic solvents can also form fountains.

The above content refers to the Encyclopedia Fountain Experiment.

GaspFountain ExperimentHere's how it works:

The basic principle is that the difference in air pressure causes the liquid to flow backwards. The so-called fountain experiment is mainly a liquid sucking phenomenon caused by the rapid and complete dissolution of the gas in the closed container in the liquid, so that a certain air pressure difference (negative pressure) between the container and the outside world is formed. So the gasp fountain is a kind of fluid mechanics.

phenomenon, which can be used to draw liquids without the help of a pump.

Formation of air pressure:

From the theory of molecular kinetics.

It can be seen that the pressure of the gas is caused by the frequent collision of a large number of molecules against the walls of the container. The collision time of a single molecule on the container wall is extremely short, and the effect is not continuous, but a large number of molecules frequently collide with the vessel wall, and the force on the vessel wall is continuous and uniform, and the ratio of this pressure to the area of the vessel wall is the pressure strength is small.

The magnitude of the air pressure versus the altitude.

Atmospheric temperature, atmospheric density, etc., generally decreasing exponentially with the increase of altitude. There are diurnal and annual variations in air pressure. During the year, the air pressure is higher in winter than in summer.

The root cause of the formation of a fountain is the pressure difference.

The liquid from the beaker under the flask is pressed into the flask using atmospheric pressure, creating a fountain at the mouth of the needle-nosed catheter.

1 volume of water can dissolve 700 volumes of ammonia (0 degrees Celsius, 1 standard atmosphere), when the water in the dropper enters the flask, the ammonia is dissolved in a large amount of water, the external atmospheric pressure will press the water into the bottle, and the remaining ammonia will be dissolved in the water entering the bottle, and finally the water will fill the flask.

The requirements for this type of experiment are:

1. The device has good air tightness.

2. The gas used can be dissolved in a large amount of liquid or the gas reacts quickly with the liquid.