Sodium metaborate

This is a special salt. It looks like clear crystals.

It is made from three things. These are sodium, boron, and oxygen. People can make it by heating certain powders together.

This salt can change when it gets wet. It can hold onto water. This helps it turn into different kinds of crystals.

This salt is very useful. It helps make strong glass. This glass does not break easily when it gets hot. It can also help weeds die.

It is a very helpful tool for science.

Sodium metaborate is a special chemical compound. It is made of sodium, boron, and oxygen. It looks like clear crystals.

This salt can change based on how much water it holds. We call these different forms hydrates. Some forms grow in cold temperatures. Others grow when it is warmer. For example, a tetrahydrate forms between -6 and 53.6 degrees Celsius. A dihydrate forms at higher heat. The salt can even absorb water from the air. This is called being hygroscopic.

People make this salt in a few ways. One way is to melt sodium carbonate and boron oxide together. You can also melt borax with sodium hydroxide. This happens at 700 degrees Celsius.

This substance has many uses. It helps make borosilicate glass. This is a strong glass. It can handle fast or uneven heat without breaking. It is also used to make herbicides. These are tools used to kill weeds. Finally, it helps change the pH of fluids used to get oil from the ground.

Sodium metaborate is a special chemical compound. It is made of sodium, boron, and oxygen. This substance appears as colorless crystalline solids. It can also be found in many different hydrates. A hydrate is a solid that holds water inside its structure. The anhydrous form, which has no water, is hygroscopic. This means it likes to pull water from the air. This compound is very important for making many different things.

How this substance works depends on its temperature. Different versions of the crystal form at different heat levels. A tetrahydrate forms between -6 and 53.6 degrees Celsius. A dihydrate forms between 53.6 and 105 degrees Celsius. A hemihydrate forms from 105 degrees up to the boiling point. When you dissolve it in water, the anion combines with two water molecules. This creates a new thing called a tetrahydroxyborate anion. The way the atoms are arranged changes as the heat changes.

Scientists have studied how these atoms sit together. In the anhydrous form, the atoms form a hexagonal crystal system. This shape contains six-membered rings. These rings are made of alternating boron and oxygen atoms. One extra oxygen atom attaches to each boron atom. All nine of these atoms lie on a flat plane. In the dihydrate form, the crystals use a triclinic system. The density of the anhydrous salt is 2.348 grams per cubic centimeter.

People can make sodium metaborate in a few ways. One way is to melt sodium carbonate and boron oxide together. You can also melt borax with sodium hydroxide at 700 degrees Celsius. Another way involves heating tetraborate to 270 degrees Celsius in a vacuum. The boiling point is 1434 degrees Celsius. This is lower than the boiling point of boron oxide. Borax has a boiling point of 1575 degrees Celsius. Boron oxide has a boiling point of 1860 degrees Celsius.

This compound helps us in our daily lives. It is used to manufacture borosilicate glasses. These glasses are very strong against uneven or fast heating. This is because they have a small coefficient of thermal expansion. Sodium metaborate is also used in the composition of herbicides. These are used to manage weeds. Finally, it can raise the pH of fluids used for oil extraction. This helps move fluids during the process of getting oil from the ground.

Sodium metaborate is a chemical compound made of sodium, boron, and oxygen. It is an important substance used in many industrial processes. This compound appears as colorless crystalline solids in various forms. It can exist in an anhydrous state, which means it contains no water. It also exists as several different hydrates. A hydrate is a solid that holds water molecules within its crystal structure. The anhydrous form is hygroscopic, meaning it pulls moisture from the surrounding air.

The structure of sodium metaborate changes based on how much water it holds. The anhydrous form uses a hexagonal crystal system. Within this system, the atoms form six-membered rings. These rings consist of alternating boron and oxygen atoms. One extra, negatively charged oxygen atom attaches to each boron atom. All nine of these atoms sit on a single flat plane. The density of this anhydrous form is 2.348 grams per cubic centimeter.

When water is added, different types of hydrates form at specific temperatures. A tetrahydrate forms between -6 and 53.6 degrees Celsius. A dihydrate forms between 53.6 and 105 degrees Celsius. A hemihydrate forms from 105 degrees Celsius up to the boiling point. The dihydrate uses a triclinic crystal system. This system is nearly monoclinic because its angles are close to 90 degrees. The dihydrate has a density of 1.905 grams per cubic centimeter.

Scientists use different methods to prepare sodium metaborate in a laboratory. One common method is the fusion of sodium carbonate and boron oxide. Another way is to fuse borax with sodium hydroxide at 700 degrees Celsius. You can also create the anhydrous salt by heating tetraborate to 270 degrees Celsius in a vacuum. When heated to very high temperatures, between 900 and 1400 degrees Celsius, the vapor shows isolated clusters. These clusters follow the formula (BO3)n. Electron diffraction studies by Akishin and Spiridonov helped reveal these linear structures.

This compound can undergo several important chemical reactions. When dissolved in water, the anion combines with two water molecules. This process creates a tetrahydroxyborate anion. Sodium metaborate can also be converted into borax through electrolysis. This happens in a concentrated aqueous solution using an anion exchange membrane. Another useful reaction is the reduction to sodium borohydride. This can be done using reducing agents at high temperatures and pressure. It can also be done by ball milling with magnesium hydride at room temperature.

Sodium metaborate is used for many practical purposes in technology and agriculture. One major use is the manufacture of borosilicate glasses. These glasses are special because they have a small coefficient of thermal expansion. This means they do not expand or contract much when temperature changes. Because of this, they resist breaking from uneven or fast heating. Sodium metaborate is also used in the composition of herbicides to manage weeds. Additionally, it is used to raise the pH of fluids during oil extraction.

Understanding the boiling points of these chemicals helps scientists manage their work. The boiling point of sodium metaborate is 1434 degrees Celsius. This is lower than the boiling point of borax, which is 1575 degrees Celsius. It is also lower than the boiling point of boron oxide, which is 1860 degrees Celsius. When borax boils, it gives off a vapor of sodium metaborate. This vapor contains a small excess of sodium oxide. These specific measurements allow chemists to control how they create and use these materials.