What is Sodium Hypochlorite?
Sodium hypochlorite is an ionic chemical compound with the formula NaOCl. It comprises sodium cation and hypochlorite anion. It is known by various other names such as antiform in, bleach etc. It is generally found in its pentahydrate state. As its anhydrous form is unstable and decomposes explosively. Sodium hypochlorite pentahydrate is a pale greenish-yellow solid which is stable and not explosive. It is widely used as a cleaning agent or as a bleach.
Sodium Hypochlorite and its Formula
In liquid form, sodium hypochlorite is a strong oxidizing agent with a greenish or yellowish tint. Because it is the active element in bleach, it is generally referred to as bleach. One sodium (Na) atom, one chlorine (Cl) atom, and one oxygen (O) atom make up the chemical formula NaClO. The hypochlorite ion (ClO-) has an ionic interaction with the sodium (Na+) ion, as shown by its chemical structure. It has a molar mass of 74.44 grams per mol.
Structure of Sodium Hypochlorite
Sodium hypochlorite is a salt made up of sodium cation and hypochlorite anion. It is also known as the sodium salt of hypochlorous acid (HOCl). Its structure is given below –
Chemical properties: Sodium hypochlorite is a powerful oxidizer. It forms salts when it combines with protic acids like HCl, while also producing poisonous chlorine gas. It also forms hypochlorous acid when it combines with certain acids (HClO). It decomposes in water into sodium and chloride ions, as well as the potent oxidizer hydroxyl radical (OH.). In addition to sodium chloride and oxygen, NaClO decomposes into sodium chloride and oxygen.
Its molar mass is 74.4 g.mol-1.
Sodium hypochlorite pentahydrate is a greenish-yellow solid.
It has chlorine-like and a sweetish odor.
Its melting point is 18 ℃.
Its boiling point is 101 ℃.
It is soluble in water.
Its density is 1.11 g.cm-3.
It is corrosive.
Sodium hypochlorite is unstable and explosive although sodium hypochlorite pentahydrate is stable at lower temperatures and non-explosive.
It decomposes at high temperatures and forms sodium chlorate and sodium chloride. The reaction is given below –
3NaOCl(aq) → 2NaCl(aq) + NaClO3(aq)
It is used in the oxidation of starch.
Oxidation of metals – Sodium hypochlorite reacts with metals and forms metal oxide by oxidizing them. The reaction is given below –
NaOCl + Mg 🡪 MgO + NaCl
Reaction with ammonia - Sodium hypochlorite reacts with NH3 and forms sodium hydroxide and NH2Cl. The reaction is given below –
NH3 + NaOCl → NH2Cl + NaOH
Reaction with monochloramine – Sodium hypochlorite reacts with monochloramine and forms sodium hydroxide and dichloramine. The reaction is given below –
NH2Cl + NaOCl → NHCl2 + NaOH
Reaction with dichloramine – Sodium hypochlorite reacts with dichloramine and forms sodium hydroxide and nitrogen trichloride. Reaction is given below –
NH2Cl + NaOCl → NCl3+ NaOH
Uses of Sodium Hypochlorite
Sodium hypochlorite is a very useful compound. It is used in many fields for various purposes. A few of its applications are listed below –
It is used as bleach. Household bleach solutions generally contain 3-8% of sodium hypochlorite by weight.
It is used for cleaning purposes such as to remove mold stains, dental stains etc.
It is used as a disinfectant. It has an antimicrobial ability which makes it very useful in hospitals as a disinfectant. It is used in Dakin’s solution as well.
It has deodorizing and caustic effects which makes it even more useful for cleaning and laundry.
It is used in the treatment of wastewater.
Due to its effectiveness against pathogenic organisms, it is used in endodontic therapy.
Soaps containing sodium hypochlorite are being used for the treatment of eczema in humans for decades.
Sodium Hypochlorite acts as a bleaching agent and disinfectant for household as well as industrial purposes.
It's also used as a disinfectant in water treatment facilities, swimming pools, some medical and dental procedures, in the food business as a deodorizer, in households as a deodorizer and cleaning agent, and in laundry detergents as a stain remover and bleach.
Sodium Hypochlorite: Summary in Tabular Form
This ends our coverage on the topic “Sodium hypochlorite”. We hope you enjoyed learning and were able to grasp the concepts. We hope after reading this article you will be able to solve problems based on the topic. If you are looking for solutions of NCERT Textbook problems based on this topic, then log on to Vedantu website or download Vedantu Learning App. By doing so, you will be able to access free PDFs of NCERT Solutions as well as Revision notes, Mock Tests and much more.
FAQs on Sodium Hypochlorite
1. Is sodium hypochlorite toxic to people?
When sodium hypochlorite is consumed, it causes stomach pain, a burning sensation, coughing, nausea, sore throat, and vomiting. On the skin or in the hair, sodium hypochlorite causes irritation and redness. Skin can become sensitive after prolonged exposure. Animals that drink water are poisoned by sodium hypochlorite.
2. When sodium hypochlorite is introduced to water, what happens to the pH level?
The pH of the water is raised due to the presence of caustic soda in sodium hypochlorite. When sodium hypochlorite dissolves in water, it forms two compounds that aid in oxidation and disinfection. Hypochlorous acid (HOCl) and the less active hypochlorite ion are the two (OCl-). The amount of hypochlorous acid generated is determined by the pH of the water. Hydrochloric acid (HCl) is used to reduce the pH while sodium hypochlorite is used to raise it. As an alternative to acetic acid, sulfuric acid (H2SO4) might be employed. When sulfuric acid is employed, fewer hazardous gases are created. Sulfuric acid is a powerful acid that reacts violently with bases and is extremely corrosive.
3. At what temperature should sodium hypochlorite be stored?
Sodium hypochlorite should be kept apart from incompatible items. Bleach should be kept away from reducing agents, organic chemicals, and acids. Sodium hypochlorite must be kept in an airtight container at temperatures below 68°F (20 degrees Celsius). The chlorine concentration of sodium hypochlorite may be less than 12.5 percent when utilized since it loses potency with time, especially in warmer conditions.
4. What Makes Filtered Sodium Hypochlorite Better than Non-Filtered Sodium Hypochlorite?
Filtration of sodium hypochlorite has a variety of advantages.
Sodium hypochlorite can be made with any sort of sodium hydroxide, including diaphragm cell caustic. This gives you more options for vendors, which usually means lower material costs and, as a result, lower manufacturing costs.
A simple supply and demand theory states that a higher-quality product can be sold for a higher price.
Because high purity sodium hypochlorite does not degrade as quickly as an ordinary grade, you can lessen the product's strength.
The amount of oxygen produced is greatly reduced. As a result, product safety has been enhanced. allowing clients to package their products without their bottles expanding due to the creation of oxygen
Customer concerns about oxygen and solids development in storage tanks, pumps, and pipes are minimized, saving money.
Sniff gas bleach can be sold as high-quality bleach after filtering.
5. On Vedantu, how can CBSE Class 11 Chemistry students find solved questions and answers about Sodium Hypochlorite?
Students should be aware that the Class 11 Chemistry syllabus is extensive, and that in order to receive good grades, they must answer all of the important questions. Students can go to the Vedantu website and download crucial Class 11 Chemistry questions on a variety of topics, including Sodium Hypochlorite. This can also assist students to grasp the fundamentals of several chapters in the 12th grade and improve their scores on the CBSE board's final examination.