Chloride

Chloride is a type of chemical compound that includes a chlorine atom. This chlorine atom can either have a negative charge, called an anion, or it can be attached to another part of the molecule by a single bond. The word "chloride" is pronounced /ˈklɔːraɪd/.

Many chloride salts, like sodium chloride, dissolve in water. These salts are very important inside our bodies. They help keep the right balance of acids and bases, send messages through our nerves, and control how water moves in and out of our cells. Other examples of chlorides include potassium chloride, calcium chloride, and ammonium chloride.

There are also chlorides that share their bonds with other atoms, called covalent chlorides. Examples of these include methyl chloride, carbon tetrachloride, sulfuryl chloride, and monochloramine. All of these different types of chloride play important roles in chemistry and in our everyday lives.

Electronic properties

A chloride ion is a chlorine atom that has gained an extra electron. This makes it larger and less tightly holding onto its outer shell. This ion does not have color and does not attract magnets. In water, most chloride ions mix easily. Some, like silver chloride, do not mix well with water. When in water, chloride ions are surrounded by water molecules.

Reactions of chloride

Chloride can change but cannot be made simpler. It can turn into chlorine gas, which can then change into other compounds like the ingredient in bleach.

Chloride can also act as a very weak base. When mixed with strong acids, it can form new compounds. For example, mixing sodium chloride with sulfuric acid makes hydrochloric acid.

We can find out if chloride is present by using silver nitrate, which creates a white substance when chloride is around. Special tools can also measure how much chloride is in a sample.

Other oxyanions

Chlorine can have different oxidation states. These states are -1, +1, +3, +5, or +7. There are also some neutral chlorine oxides that we know about.

Chlorine oxidation state	−1	+1	+3	+5	+7
Name	chloride	hypochlorite	chlorite	chlorate	perchlorate
Formula	Cl⁻	ClO⁻	ClO⁻ ₂	ClO⁻ ₃	ClO⁻ ₄
Structure

Occurrence in nature

The structure of sodium chloride, revealing the tendency of chloride ions (green spheres) to link to several cations.

Chloride is found in seawater, where it is very common. It is also in places like the Great Salt Lake in Utah and the Dead Sea in Israel. Many chloride salts dissolve in water, so they are often only found in dry places or deep underground. Some minerals that contain chloride include halite (sodium chloride), sylvite (potassium chloride), and others.

Chloride is very important for living things. It helps keep the right balance of fluids in our bodies and is needed for nerves to send signals. It is also used to make a special acid in our stomachs that helps us digest food. Our bodies need chloride to stay healthy, and we get it from the food we eat.

Production

The chlor-alkali industry uses a lot of energy to change salty water into useful chemicals. This process makes chlorine and sodium hydroxide. These are important for creating many things we use every day. It works through special reactions that turn the ingredients into new products.

Examples and uses

An example is table salt, which is sodium chloride with the chemical formula NaCl. In water, it separates into Na⁺ and Cl⁻ parts. Salts such as calcium chloride, magnesium chloride, and potassium chloride have many uses, from medical treatments to helping cement stay strong.

Calcium chloride (CaCl₂) is sold in pellet form to help remove moisture from rooms and care for lawns. It is also used to keep unpaved roads in good condition and to strengthen roadbases for new construction. In addition, calcium chloride is often used as a de-icer because it helps ice melt when spread on surfaces.

Examples of chlorides that share electrons in their bonds are phosphorus trichloride, phosphorus pentachloride, and thionyl chloride. These are used to help change other chemicals in reactions.

Water quality and processing

Chloride is important in making clean drinking water through a process called desalination, where salt is removed from water. In the petroleum industry, chloride levels in the mud system are watched closely. Changes in chloride levels can show if a well is in a salty area or if the sand quality is not good.

Chloride is also used to check if river and groundwater have harmful materials, as it is found in both clean water and sewage. Many water companies use chloride to test how clean rivers and drinking water sources are.

Food

Chloride salts like sodium chloride are used to preserve food and as nutrients or condiments.