Sodium hypochlorite

Many people know this as bleach.

It is a liquid used for cleaning. It can make clothes look bright. It also kills germs.

This liquid can be unsafe. You must not mix it with other cleaners. Mixing it with some soaps can make bad air.

This bad air can be hard to breathe. It is also very strong. It can hurt your skin.

Always be careful when you use it. It is a very helpful tool for a clean home.

Many people know this as bleach.

Its scientific name is sodium hypochlorite. It is a chemical used to clean. It works as a disinfectant to kill germs. It also acts as a bleaching agent to make clothes look bright.

This chemical can be tricky to handle. In its pure, dry form, it is very unstable. It can even explode if it gets hot or is rubbed. Most of the time, we use it as a liquid solution. This liquid is often a pale greenish-yellow color. In this form, it is much safer to use.

Safety is very important when using bleach. You should never mix it with other cleaners. For example, mixing it with acids can let out chlorine gas. This gas is toxic and hard to breathe. Mixing it with ammonia is also dangerous. This can make gases called chloramines.

Factories make bleach in a few ways. One way is to pass chlorine gas into a liquid called sodium hydroxide. Another way is through electrolysis. This uses electricity to make the parts needed for bleach. This is the main way it is made today.

You probably have a bottle of bleach in your laundry room.

Its scientific name is sodium hypochlorite. This chemical is a very important tool for cleaning. It works as a disinfectant to kill germs on surfaces. It also acts as a bleaching agent to make clothes look bright. Most people find it in a pale greenish-yellow liquid solution. This liquid is much easier to use than the pure form.

Sodium hypochlorite works by releasing chlorine into a liquid. This released chlorine is the part that actually does the cleaning. In its pure, dry form, the chemical is very unstable. It can actually explode if it gets too hot or experiences friction. To make it safer, scientists can turn it into a solid called a pentahydrate. This version is a pale greenish-yellow crystal. It is much more stable if you keep it in a refrigerator.

People have used this chemical for a very long time. Claude Louis Berthollet first made it in his lab in 1789. He worked at the Quai de Javel in Paris, France. He made a liquid called "Eau de Javel" by using potash lye. Later, Antoine Labarraque used a cheaper soda lye instead. This created a different version called "Eau de Labarraque." These early discoveries helped lead to the bleach we use today.

There are many ways to make sodium hypochlorite in a factory. One common way is to add chlorine gas to a sodium hydroxide solution. Another way is a method called the chloralkali process. This was patented by E. S. Smith near the end of the 1800s. This process uses electricity to break down a salty liquid called brine. Today, a version called the Hooker process is the main way it is made. Factories must keep the liquid below 40 °C to keep it stable.

Even though it is helpful, you must use bleach very carefully. It is a corrosive substance that can be a safety risk. You should never mix liquid bleach with other cleaning products. Mixing it with acids can release a toxic gas called chlorine. Mixing it with ammonia is also dangerous for your health. This reaction creates different gases called chloramines. Always follow safety rules when using this strong cleaner.

Sodium hypochlorite is an inorganic chemical compound with the formula NaClO. It is most commonly encountered as a dilute aqueous solution, which is a liquid made by dissolving the chemical in water. In the household, this liquid is widely known as bleach or chlorine bleach. It serves two primary roles: it is a powerful disinfectant and a strong bleaching agent.

Because it is an alkaline substance, it has a high pH, often reaching 11 or higher. This alkalinity makes it a weak base, which influences how it behaves in different environments.

The chemical works through a process of releasing chlorine. In a solution, the sodium hypochlorite is unstable and decomposes. This decomposition liberates chlorine, which is the active principle that performs the cleaning and disinfecting. The specific form of chlorine present depends heavily on the pH level of the liquid. At a pH below 2, most of the chlorine exists as dissolved elemental chlorine. When the pH is higher than 7.4, the majority of the substance exists as hypochlorite anions. At a pH of about 4, the amount of undissociated hypochlorous acid is at its highest.

Sodium hypochlorite can exist in several different physical states. The anhydrous form is the pure, dry version of the chemical. This version is highly unstable and can decompose explosively if it is heated or subjected to friction. To make it safer, it can be crystallized as a pentahydrate, which is a pale greenish-yellow solid. This pentahydrate contains 44% NaOCl by weight and is much more stable, especially if kept under refrigeration. Another stable form is the dihydrate, which can be produced by carefully excluding chloride ions. This dihydrate is much more resistant to decomposition during storage.

The history of this compound begins in the late 18th century. In 1789, Claude Louis Berthollet produced potassium hypochlorite in his laboratory in Paris, France. He did this by passing chlorine gas through a solution of potash lye. The resulting liquid was called "Eau de Javel." Later, Antoine Labarraque used a cheaper soda lye to produce sodium hypochlorite. This version was known as "Eau de Labarraque." By the end of the 19th century, E. S. Smith patented the chloralkali process. This method uses the electrolysis of brine to produce the necessary ingredients for bleach.

Industrial production today often relies on the Hooker process. This is an improved version of the chloralkali method. In this process, chlorine is passed into a cold, dilute solution of sodium hydroxide. This reaction produces both sodium hypochlorite and sodium chloride, which is common salt. To prevent the formation of unwanted sodium chlorate, the solution must be kept below 40 °C using cooling coils. Commercial household bleach is usually a solution containing between 3% and 8% sodium hypochlorite. Some products, like laundry bleach, may be sold at a 2.6% concentration.

While sodium hypochlorite is useful, it presents significant safety risks due to its corrosive properties. It is vital never to mix liquid bleach with other cleaning products. If bleach is mixed with acids, such as those found in limescale removers, it releases toxic chlorine gas. Mixing bleach with ammonia does not release chlorine, but it does produce dangerous chemicals called chloramines. These include nitrogen trichloride. In cases involving excess ammonia and sodium hydroxide, a substance called hydrazine may also be generated. Always handle these chemicals with extreme care to avoid these dangerous reactions.

Beyond simple cleaning, sodium hypochlorite is involved in complex chemical reactions. It can act as an oxidant, which means it can strip electrons from other molecules. For example, it can oxidize organic compounds like starch, alcohols, and sulfides. In industrial settings, the decomposition of hypochlorite is sometimes used to produce sodium chlorate. This occurs when the solution is heated, causing the hypochlorite to disproportionate. This means the chemical breaks down into chloride and chlorate. Scientists can also use titration to measure the strength of a bleach solution by monitoring how it reacts with other chemicals.