Mercury chloride facts for kids

Mercury chloride refers to two different chemical compounds made from the element mercury and chlorine. These compounds are quite different from each other, especially in how toxic they are and how well they dissolve in water.

One type is called Mercury(I) chloride, also known as calomel. The other is Mercury(II) chloride, often called corrosive sublimate. Both have been used by people for a long time, but their dangers mean they are not used as much today.

What is Mercury Chloride?

Mercury chloride is a chemical compound. This means it is made when two or more different elements join together. In this case, it's mercury (a heavy metal) and chlorine (a gas). These elements combine in different ways to make the two types of mercury chloride. The number in their names, like (I) or (II), tells us how the mercury atoms are bonded with the chlorine atoms. This small difference makes a big change in their properties.

Mercury(I) Chloride: The Calomel Story

Mercury(I) chloride is also known as calomel. Its chemical formula is Hg₂Cl₂. It is a white, solid powder.

• Less Toxic: Compared to mercury(II) chloride, calomel is much less harmful.
• Insoluble: It does not dissolve easily in water. This is one reason it is less toxic, as it doesn't spread as easily in the body.

Uses of Calomel

For many years, calomel was used in medicine. Doctors used it as a laxative (to help with digestion) and to treat certain diseases. However, because it contains mercury, it is not used for medicine anymore. Today, calomel is sometimes used in science. It can be found in special electrodes (parts of electrical devices) used in chemistry labs. It is also sometimes used in fungicides, which are chemicals that kill fungi.

Mercury(II) Chloride: The Corrosive Sublimate

Mercury(II) chloride is also known as corrosive sublimate. Its chemical formula is HgCl₂. It is also a white, solid powder, but it is very different from calomel.

• More Toxic: This compound is very poisonous. Even small amounts can be dangerous.
• Soluble: Unlike calomel, it dissolves easily in water. This makes it much more dangerous because it can spread quickly in the body or environment.

Uses of Corrosive Sublimate

In the past, mercury(II) chloride was used as a strong disinfectant. People used it to clean wounds or to preserve wood. It was also used in photography and in some chemical reactions. However, because it is so toxic, its use has greatly decreased. Today, it is mostly used in laboratories for specific chemical processes. It is handled with extreme care due to its dangerous nature.

Why is Mercury Dangerous?

All forms of mercury can be harmful to living things. Mercury compounds, like mercury chloride, can affect the brain, kidneys, and nervous system. This is why scientists and doctors are very careful when working with mercury. They make sure to handle it safely and dispose of it properly. The goal is to protect people and the environment from its harmful effects.

See also

In Spanish: Cloruro de mercurio para niños