Sodium Borohydride: Properties, Uses, and Safety

Introduction

Sodium borohydride is a white crystalline powder that has been extensively used as a reducing agent in organic and inorganic chemistry. This article will discuss the properties, uses, and safety precautions associated with sodium borohydride.

Chemical Properties

Sodium borohydride has the chemical formula NaBH4 and a molar mass of 37.83 g/mol. It is highly soluble in water, and its aqueous solution is basic. Sodium borohydride reacts with water to release hydrogen gas, and it decomposes rapidly in acidic solutions.

Synthesis and Production

Sodium borohydride is usually prepared by reacting sodium hydride with trimethyl borate or boron trioxide in the presence of an alcohol solvent. Alternatively, it can be produced by reducing boron trioxide with hydrogen gas in the presence of sodium metal.

Applications

Sodium borohydride is widely used as a reducing agent in various organic and inorganic reactions. It is a mild and selective reducing agent that can reduce a wide range of functional groups, including carbonyl, imine, and nitro groups. In organic synthesis, sodium borohydride is used to reduce aldehydes and ketones to alcohols, esters to alcohols, and carboxylic acids to aldehydes. It is also used in the synthesis of pharmaceuticals and fine chemicals.

In inorganic chemistry, sodium borohydride is used to reduce metal ions to their respective metals. It is also used in the production of hydrogen gas from water, and as a hydrogen storage material for fuel cells.

Safety Precautions

Sodium borohydride is a highly reactive chemical and should be handled with care. It can react violently with water, acids, and oxidizing agents, producing hydrogen gas. The powder form of sodium borohydride is highly flammable and can ignite spontaneously in air. It is also a strong reducing agent that can cause skin and eye irritation upon contact. Therefore, it is important to wear appropriate personal protective equipment (PPE) when handling sodium borohydride.

Storage and Handling

Sodium borohydride should be stored in a dry, cool, and well-ventilated area. It should be kept away from moisture, heat, and oxidizing agents. The powder form of sodium borohydride should be stored in a tightly closed container to prevent the absorption of moisture and the release of hydrogen gas. When handling sodium borohydride, it is important to use proper ventilation and avoid inhalation of the powder or solution.

Conclusion

Sodium borohydride is a widely used reducing agent in organic and inorganic chemistry. It has many applications in various fields, including pharmaceuticals, fine chemicals, and hydrogen storage. However, it is a highly reactive chemical that requires proper handling and storage to ensure safety. By following the necessary precautions and guidelines, sodium borohydride can be used safely and effectively in a laboratory setting.