How to prepare ferrous hydroxide 15

Glad for your question. Take boiled distilled water (in order to remove oxygen as much as possible) and dissolve a small amount of sodium hydroxide.

Draw a small amount of freshly prepared ferric chloride solution with a washed glue tip dropper, extend the rubber tip dropper into the bottom of the sodium hydroxide solution, and squeeze out the newly prepared ferric chloride solution at this time to obtain ferrous hydroxide. The phenomenon that should be observed is that the white ferrous hydroxide rapidly turns into a gray-green substance, and finally turns into a reddish-brown solid iron hydroxide.

Due to the limited experimental conditions, it is difficult to succeed in this experiment, and hydrogen should be introduced into the NaOH solution first to fully expel the oxygen and create reducing conditions. Good luck with your experiment!!

It is recommended to use purified water as a solution (to avoid liquefaction), you can put the iron in dilute hydrochloric acid, and add excess sodium hydroxide solution to it after the reaction, there will be gray-green precipitate formation, then you can use the way of flushing hydrogen gas into the long-neck funnel to wash and filter the precipitate. Store in hydrogen, do not evaporate.

How to prepare ferrous hydroxide colloids.

Ferrous hydroxide can be used to react with ferrous sulfate solution and sodium hydroxide to generate ferrous hydroxide precipitate and sodium sulfate, and ferrous hydroxide can be obtained by filtration.

Inject a small amount of freshly prepared ferrous sulfate solution into the test tube (in order to make the preparation of ferrous hydroxide successful, heat the ferrous sulfate solution first to remove the dissolved oxygen), then drop a few drops of kerosene into it, use a rubber tip dropper to absorb the sodium hydroxide solution, insert the tip of the dropper into the liquid surface of the solution in the test tube, and drop the sodium hydroxide solution drop by drop.

The reaction equation is as follows: FeSO+2NaOH==Fe(OH) NaSO.

Ferrous hydroxide can be prepared by adding an excess sodium hydroxide solution to a sodium ferrous iron solution. During the reaction, the hydrogen ions in the sodium hydroxide will combine with the iron ions in the sodium ferrous solution to form an ferrous hydroxide precipitate.

The specific preparation method is as follows:

Sodium ferrous iron (FENA) and sodium hydroxide (NaOH) are added to separate containers.

Add the sodium hydroxide solution drop by drop to the sodium ferrous iron solution, stirring constantly.

When the solution becomes turbid and precipitates, stop adding the sodium hydroxide solution.

Filter the solution, wash the pellet, and rinse with hot water.

The precipitate is dried to obtain ferrous hydroxide.

Please note that this is only a laboratory preparation method and in practice, the preparation method of ferrous hydroxide may vary.

Ferrous hydroxide is oxidized in air to form iron hydroxide, and its reaction equation is 4Fe(OH) O +2H O ==4Fe(OH).

Properties of ferrous hydroxide:

Ferrous hydroxide Fe(OH)2 is a white solid at room temperature and pressure, but it is easily oxidized to Fe(OH)3, so it is mostly reddish-brown.

It quickly dissolves in dilute acid to form ferrous salts. It is a strong reducing agent in alkaline solution. When ferrous hydroxide powder is sprayed in the air, it immediately burns and emits sparks.

The relative density is three .four. Decomposes when heated. Insoluble in alkaline solution, insoluble in water, soluble in ammonium chloride.

Preparation of ferrous hydroxide:

Pure ferrous sulfate FeSO4·7H2O crystallization is selected, and dissolved in oxygen-free water after boiling and cooling under the condition of pre-ventilation nitrogen, at a concentration of about moles per liter. Prepare about 10 liters of concentrated sodium hydroxide in water. This solution is prepared with oxygen-free water.

Under stirring, sodium hydroxide solution is added dropwise to the ferrous sulfate solution, and after the gray-green precipitate settles, the upper clarifier is sucked out with a siphon and washed repeatedly with oxygen-free water. Filter and dry at room temperature. Note that this preparation must be carried out in pure nitrogen.

The above content reference: Encyclopedia - ferrous hydroxide.

(1) Preparation principle of ferrous hydroxide:

Experimental phenomena for the preparation of FeSO4 + 2NaOH ==Na2SO4 + Fe(OH)2(2) ferrous hydroxide:

The white precipitate is present for a longer period of time.

Later the white turned gray-green, and finally reddish-brown!

The reaction equation for the preparation of ferrous hydroxide is: FeSO4+2NaOH=Fe(OH)2+Na2SO4.

Ferrous oxide belongs to the hexagonal crystal system, and the lattice constant a0=, c0=. It is easily oxidized in the air and turns reddish-brown. It quickly dissolves in dilute acid to form ferrous salts. It is a strong reducing agent in alkaline solution.

When ferrous hydroxide powder is sprayed in the air, it immediately burns and emits sparks. Relative density. Decomposes when heated. Insoluble in alkaline solution, insoluble in water, soluble in ammonium chloride.

Industrial Method. The manufacture of ferrous hydroxide is usually done by adding alkali metal hydroxides to a solution of ferrous salt salts, which must be carried out in an inert atmosphere (e.g., nitrogen, argon) because they are easily oxidized. Pure Fe(OH)2 is white, but when oxidized, it changes from green to dark green.

Method 1: Prepare a dilute aqueous solution of ferrous sulfate and sodium hydroxide with water that has been boiled to remove the air dissolved in it. Put the ferrous sulfate solution into a small bottle, and add sodium hydroxide aqueous solution to it to make it exactly a full bottle.

When the liquid volume is insufficient, water can be added to remove the air and then sealed and left temporarily.

The above content reference: Encyclopedia - ferrous hydroxide.

1. Ferrous sulfate is prepared, and copper sulfate solution is reacted with iron to generate ferrous sulfate and copper, and the reaction equation is as follows

Cuso +Fe==Feso +Cu (the type of reaction belongs to the displacement reaction).

2. Prepare ferrous hydroxide, react with the prepared ferrous sulfate solution and sodium hydroxide to generate ferrous hydroxide precipitate and sodium sulfate, filter to obtain ferrous hydroxide, and the reaction equation is as follows:

Feso +2NaOH ==Fe(OH) Na SO (The type of reaction belongs to metathesis).

Inject a small amount of freshly prepared ferrous sulfate solution into the test tube, then drop a few drops of kerosene into it, use a rubber tip dropper to absorb the sodium hydroxide solution, insert the tip of the dropper into the test tube under the liquid surface of the solution, drop in the sodium hydroxide solution drop by drop, and observe the phenomenon.

In addition, in order to make the preparation of ferrous hydroxide successful, the ferrous sulfate solution is heated to remove the dissolved oxygen.