A Chemical Question: How to Prepare Sodium in Sodium Chloride?

Before talking about the method to prepare sodium in sodium chloride, we will introduce some properties of sodium and its important usage. Sodium, a metallic element, located in Period 3, Group IA in the Periodic Table, is a representation of the alkali metal elements with a soft texture and very active chemical properties. It can react with water to form sodium hydroxide, releasing hydrogen gas, which is widely distributed in the form of salt on land and in the sea.

Wide application of sodium metal

1. Sodium metal is widely applied in the chemical industry. It can be used to produce sodium hydroxide and hydrogen. Sodium hydroxide, a compound also known as caustic soda, can be obtained by this reaction. It is a key chemical raw material.

2. When some important organic compounds are needed to synthesize, sodium metal can be used to act as a strong reducing agent, such as alcohols and ethers. So it has a wide application in the scope of chemistry, medicine, and agriculture

3. Sodium metal also has a significant effect on scientific research. For example, it can be used to observe and study the nano spectral lines of sodium metal, the emission, and absorption which provide important information for scientific research. 

4. Sodium metal also can be used in the field of electric light sources, such as high-pressure sodium lamps, which applies to many indoor and outdoor lighting occasions.

Preparation of sodium in sodium chloride by electrolysis

According to the introduction above, it is not hard to find the importance of sodium metal. So many researchers are devoted to studying the method of obtaining sodium in sodium chloride. To produce sodium metal from sodium chloride, the molten sodium chloride can be electrolyzed, which is the main method of preparing sodium in industry. The principle of electrolysis is using ions in an electrolyte solution to undergo a redox reaction in the presence of an electric field, thereby reducing sodium ions to sodium metal, which has the advantage of simple operation, low cost, and high yield.

The equipment for the electrolysis method mainly consists of an electrolysis tank, power supply, electrodes, and brine. The electrolysis tank is an airtight container with two electrodes inside, the anode and the cathode. The anode is usually made of materials such as platinum and titanium, while the cathode is made of sodium metal.

Sodium chloride is a common solution of an electrolyte. During electrolysis, a power source provides electrical energy that causes a redox reaction of chlorine ions on the anode to produce the gas chlorine. Meanwhile, sodium metal can be produced through sodium ions on the cathode with a reduction reaction. The sodium metal is deposited on the cathode, which can eventually be removed from the cathode by gradually increasing in thickness over time. 

Preparation of sodium in sodium chloride by Aluminium reduction method

Sodium chloride and aluminum powder are mixed well and then heated. The aluminum reduces the chloride ions in sodium chloride, releasing gas and producing a sodium-aluminum alloy, and then the residual aluminum and other impurities are removed by distillation or vacuum heating to obtain pure sodium. This method has the advantages of fast reaction speed and high purity.

Using a thermally reducing reductant to reduce the metal from its compounds, which is the principle of thermal reduction smelting of metals, a redox reaction. This process complies with electrons lost and gained. 

The equipment for the thermal reduction method includes a reactor, a heating furnace, a sodium-aluminium alloy, and so on. Sodium-aluminum alloy and sodium chloride are added to the reaction kettle, which is then heated to a high temperature, where sodium ions and metallic aluminum react to form sodium metal and aluminum chloride. Finally, the reaction product is cooled and the sodium metal is separated from it.

Conclusion

In general, sodium metal is widely used and plays an important role in the fields of chemical production, scientific research, electric light sources, and so on. So it is necessary to introduce methods to replace sodium in sodium chloride. Electrolysis is the main method for the production of sodium. If a small amount of sodium metal is needed, it is a better choice to adopt the thermal reduction method. No matter which method is used, the preparation of sodium metal must be paid more attention to because it has strong reducibility and activity, and it is easy to react with water to produce hydrogen, maybe causing fire and explosion.