Preparation method of stable ferrous hydroxide

Abstract

The invention relates to a preparation method of stable ferrous hydroxide .The method comprises the steps that distilled water is heated to be boiling, nitrogen is introduced simultaneously, and a NaOH solution and a FeSO4 solution are prepared with the treated distilled water separately; two injectors are taken and used for extracting the treated distilled water to be used respectively, and repeated push and pull are conducted on the injectors to enable the injector walls to be infiltrated; one injector is used for extracting the FeSO4 solution, an injection port is sealed immediately, the other injector is used for extracting the NaOH solution, and 1-5 mL of the NaOH solution is pushed out and discarded after the NaOH solution is extracted; a needle of the injector containing the NaOH solution is inserted into the injector containing the FeSO4 solution, the NaOH solution is slowly pushed into the injector, the two solutions are mixed for a reaction, and a white ferrous hydroxide precipitate is generated .According to the preparation method of stable ferrous hydroxide, it is guaranteed that almost no dissolved oxygen exists in the boiled water, the white ferrous hydroxide precipitate can be observed for a long time, the safety coefficient is high, devices and instruments with potential safety hazards are not used, no harmful substance is generated, and safety and environmental friendliness are achieved.

Description

technical field [0001] The invention relates to a preparation method of stable ferrous hydroxide, which belongs to the field of chemistry teaching. Background technique [0002] Fe(OH) 2 The preparation is a common high school classroom demonstration experiment. This experiment is a difficult point in middle school chemistry teaching. In the textbook, the sodium oxide solution is squeezed into the newly prepared ferrous sulfate solution with a dropper. Ferrous iron is easily oxidized in the air, and it is difficult to see Fe(OH) in the traditional preparation method. 2 The technical problem of the white flocculent precipitate, the resulting precipitate quickly turns gray-green and finally reddish brown, and the relationship between the color change and the oxygen flux cannot be clearly observed and calculated. At present, there are mainly the following methods to solve the above problems: [0003] (1) Preparation of FeSO 4 The distilled water and NaOH solution used in th...

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Problems solved by technology

However, it cannot be controlled by Fe(OH) at different concentrations 2 Generate Fe(OH) 3 Observation experiment of continuous color change, and the generated H 2 S is a poisonous gas, which poses a safety hazard

[0008] To sum up, the above methods all have some problems such as potential safety hazards, poor effect or not suitable for classroom demonstrations.

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