What is the basis for the selection of the gas generator for the production of gas generators?

There are two kinds of gas generating devices, one is the gas production device for the contact and reaction of solid and liquid, the other is to heat --- fixed test tube, and in the latter device, when fixing the test tube, the mouth of the --- test tube should be slightly inclined downward.

The reason --- prevent the condensate generated at the mouth of the test tube from backing up and bursting the test tube.

If potassium permanganate is used to produce oxygen, a small piece of cotton should be placed --- the mouth of the test tube ---to prevent potassium permanganate powder from entering the catheter.

The way to check whether a bottle of gas is oxygen is --- to use a wooden strip with sparks, go deep into the bottle, and if the wooden strip rekindles, it proves that it is oxygen.

The methods of collecting oxygen are --- drainage method and upward exhaust air method.

If the gas prepared by heating is collected by draining the water method, after the experiment, the catheter should be moved out of the water surface first, and then the alcohol lamp should be extinguished --- ---, because the temperature of the test tube will be reduced after the alcohol lamp is removed --- prevent the temperature of the test tube from being reduced, and the water in the sink will flow back, causing the hot test tube to burst.------

There are a lot of inscriptions in this question, hehe.

There are two kinds of gas generators, one is the gas generator for the contact and reaction of solid and liquid, and the other is (solid heating reaction device - solid heating device). In the latter device, when fixing the tube, it should be made (tube clamp) for the reason (the reaction needs to be heated). If potassium permanganate is used to produce oxygen, the mouth of the test tube should be tilted downward (to prevent the water from backing up during the reaction and rupturing the test tube).

The method of checking whether a bottle of gas is oxygen (put a wooden strip with sparks into the mouth of the gas collection cylinder to see if the wooden strip is re-ignited), and the method of collecting oxygen is (upward exhaust air), respectively, using the properties of oxygen as (insoluble in water) and (heavier than air). If the heated gas is collected by draining, the test should be completed by removing the catheter and then extinguishing the alcohol lamp to prevent the water in the tank from backflowing and causing the test tube to burst

The basis is as follows:It depends on the state of the reactants and the reaction conditions. The choice of the generator for the production of gases in the laboratory is based on the state of the reactants and the conditions of the reaction.

The laboratory preparation method of gas is mainly compared and summarized from the aspects of drugs, reaction principles, generating devices, collection devices, inspections, inspections and precautions for experimental operation, and the general ideas and methods of laboratory gas production are summarized.

Introduction:

In a chemical reaction, the substances that can participate in the reaction are called reactants, which refer to the substances that can be consumed in a chemical reaction. Solvents and catalysts involved in chemical reactions are not counted as reactants.

When writing such ion equations, it is necessary to first find out the ratio of the amount of reactant species, and if the ratio relationship is not told, the order of dropwise addition. Generally speaking, there is not enough reactant in the dropper at the beginning of the dropper, and there is too much reactant in the Erlenmeyer flask (or reaction vessel such as a beaker).

The collection device is based on whether the density of the gas (generally compared with air) is smaller than that of the upward air exhaust method, and vice versa, whether it can be dissolved in water (reminder that the last air to be collected is to collect carbon dioxide, because carbon dioxide is slightly soluble in water). There are two methods of collecting oxygen: upward air exhaust and drainage.

In the case of liquid-to-liquid reactions or liquid-to-solid reactions, a device consisting of a long-necked funnel and an Erlenmeyer flask is used, and in the case of solids and solids, a test tube is sufficient. Therefore, the first generator is used in the preparation of hydrogen peroxide, and the second type is used for potassium permanganate.

The generator is selected based on the state of the reactants and the reaction conditions. If the state of the reactants is solid, and the reaction conditions need to be heated, the device shown in Figure 1 (oxygen production device) is selected; If the reactants are solid or liquid, and the reaction conditions do not need to be heated, the device shown in Figure 2 or Figure 3 (hydrogen or carbon dioxide production unit) is used.

1. The state of the reactants.

2. Reaction conditions.

1.state of reactants (solid, liquid); 2.Reaction conditions (room temperature, heating) supplement: the idea of preparing gas in the laboratory, the principles of designing experiments and the factors that should be considered in the selection of gas collection devices:

Ideas:1Select the appropriate reaction, reactants, reaction conditions, and reaction rate; 2.Selection of appropriate experimental setup; 3.Choose a reasonable gas inspection and full inspection method.

Principles: economical (i.e. low cost), environmentally friendly, and economical of medicines.

Factors to consider when choosing a gas collection device:1solubility of the prepared gas in water; 2.whether the gas produced can react with water; 3.The magnitude of the difference in the density of the prepared gas compared to air.

We hope you find the above helpful

First, solid-liquid room temperature devices (Qipu generators, or simple separating funnels and flasks) are commonly used to produce hydrogen and carbon dioxide.

Good shelter. Second, the fixed night heating device (iron frame and flask) is commonly used to prepare chlorine sock liquid gas, oxygen....

Third, the solid heating device (iron frame plus test tube) often produces ammonia.

The gas generator and collector can also be deformed

Generating device: When mixing solid and liquid without heating to generate gas (such as zinc and hydrochloric acid to make H2), test tubes, single-hole rubber stoppers, trachea tubes or jars, double-hole rubber stoppers, long-neck funnel (separating funnel grinding bucket) guide the old bucket trachea.

Collection device: use gas washing cylinders (including abrasive length and short output and short in and long out, drainage and exhaust air can be used), use glass sheet sink and gas collection cylinder to discharge air (insoluble or insoluble gas), use glass sheet and gas collection cylinder to discharge air up or down (gas non-toxic).

Solid and non-heating device.

It is used for two or more solid chemical reactions and does not require heating.

It is used for one or more solid chemical reagents and another or more liquid chemical reagents and reactions, and requires heating.

For use with one or more solid chemical reagents and another or more liquid chemical reagents and reactions, and does not require heating.

Drainage gas collection method: suitable for gases that are difficult to dissolve in water or not easily soluble in water and do not react chemically with water. The gas collected by this method is relatively pure; When a large bubble emerges from the edge of the mouth of the gas collector cylinder, it indicates that the gas has been collected.

Upward air exhaust method: It is suitable for gases that are denser than air and do not react with any components in the air under the same conditions. During operation, attention should be paid to extending the catheter mouth close to the bottom of the gas collection cylinder, so as to facilitate the exhaustion of the air in the gas collection cylinder as soon as possible.

At the same time, the mouth of the gas collection cylinder should be covered with a glass sheet to stabilize the airflow. The gas collected by this method is relatively dry, but the purity is poor, and it needs to be filled.

Downward air exhaust method: It is suitable for gases that are less dense than air and do not react with any components in the air under the same conditions. During operation, attention should be paid to extending the catheter mouth close to the bottom of the gas collection cylinder, so as to facilitate the exhaustion of the air in the gas collection cylinder.

The gas collected by this method is relatively dry, but the purity is poor, and it needs to be filled.

Pay attention to the problem when using potassium permanganate to produce oxygen:

The mouth of the test tube should be slightly inclined downward to prevent the water in the drug from turning into water vapor after being heated, and then condensing into water droplets and flowing back to the bottom of the test tube, so that the test tube will burst.

The trachea should not be too long into the tube, as long as the rubber plug is exposed a little, so that the gas can be easily exported.

The drug should not be gathered at the bottom of the test tube, but should be spread flat at the bottom of the test tube so that it is evenly heated.

The iron clamp should be clamped about 1 3 places away from the mouth of the test tube.

The outer flame of the alcohol lamp should be heated at the drug site. When heating, preheating is carried out first, that is, the alcohol lamp is moved back and forth under the test tube to let the test tube be heated evenly, and then the parts of the quasi-drug with poor chain loss are heated.

When collecting oxygen by drainage, it is not advisable to collect oxygen immediately if there are bubbles coming out of the catheter orifice. Because it is air that is emitted at the beginning of the void, it can only be collected when the bubbles emerge evenly and continuously.

When heating potassium permanganate to produce oxygen, do not forget to put a ball of soft cotton at the mouth of the test tube, so as to prevent small particles of potassium permanganate from entering the trachea and blocking the trachea.

Don't forget to check the airtightness of the device before starting the experiment.

At the end of the experiment, remove the air duct from the sink and remove the alcohol lamp to prevent water from backing up and bursting the tube at the bottom of the tube.

The cylinder that collects the oxygen should be covered with a glass sheet and placed on the table (because oxygen is denser than air).