Comparison of properties of NaHCO3 and Na2CO3?

Open Categories: Chemicals, Salts, Sodium Salts, Carbonates, Strong Bases and Weak Acids

sodium carbonate

Chemical Formula Na2CO3

Molecular Weight 105.99

Common Name Soda, Soda (Historically, it was generally transported across the country via Zhangjiakou and Gubei Kou. Therefore, it is also called "mouth soda".)

Appearance white powder or fine crystals (anhydrous pure)

Taste astringent

Relative density (water = 1) 2.532

Melting point 851 ° C

Classification of strong bases and weak acids

Stability of the high temperature can be decomposed to produce sodium oxide and carbon dioxide. Prolonged exposure to air can absorb moisture and carbon dioxide in the air, generating sodium bicarbonate and hard lumps. Moisture absorption is very strong , it is easy to form hard lumps, and does not decompose at high temperatures. There are 3 kinds of sodium carbonate containing water of crystallization: Na2CO3-H2O, Na2CO3-7H2O and Na2CO3-10H2O.

SolubilityEasily soluble in water, slightly soluble in anhydrous ethanol, insoluble in propanol.

Sodium carbonate is easily soluble in water, is a weak acid salt, dissolved in water, hydrolysis reaction occurs, making the solution alkaline, has a certain degree of corrosiveness, and can be neutralized with the acid reaction to produce the corresponding salt and release carbon dioxide.

Production of sodium carbonate in the laboratory: 2NaOH + CO2 = Na2CO3 + H2O. sodium carbonate in nature (such as salt lakes) is known as natural alkali, in ancient times it was used as a detergent and used for dyeing and printing. 1791 began to produce sodium carbonate with salt, sulfuric acid, coal, limestone as raw materials, is the Lubran method, the method of raw materials are not fully utilized, poor labor conditions, In 1859, Solvay of Belgium used table salt, ammonia and carbon dioxide as raw materials to precipitate sodium bicarbonate from the solution at room temperature, and heated it to decompose it into sodium carbonate, which has been used until now. 1943, China's Hou Deping, combined with the lack of salt in China's interior, improved the Solvay method by combining the two major industries of soda ash and ammonia synthesis, and producing sodium carbonate and fertilizer ammonium chloride at the same time. Sodium carbonate and fertilizer ammonium chloride, greatly improving the utilization rate of salt, is Hou's alkali method. Sodium carbonate is used in soap, paper, detergent production, as a flux in the metallurgical industry, water softener.

Technical indicators of sodium carbonate:

Indicators Item Indicator

(Class 1) (Class 2) (Class 3)

Total alkali (%) 99 98 96

Chloride (%) 0.5 0.9 1.2

Water-insoluble matter (%) 0.04 0.1 0.15

Ferrous (%) 0.004 0.006 0.010 0.006 0.010

Sulfate(%) 0.03 0.08 ----

Loss on burning(%) 0.8 1.0 1.3

Use It is one of the most important chemical raw materials, used in the production of chemicals, cleaning agents, detergents, and also used in the production of photographic techniques and pharmaceuticals.

Most of it is used in industry, and a small part is used for civil use. In the industrial soda ash, mainly light industry, building materials, chemical industry, accounting for about 2/3; followed by metallurgy, textile, petroleum, national defense, medicine and other industries. Glass industry is the largest consumer of soda ash, 0.2 tons of soda ash per ton of glass consumption. Chemical industry is used to make water glass, sodium dichromate, sodium nitrate, sodium fluoride, baking soda, borax, trisodium phosphate and so on. It is used in metallurgical industry as smelting flux, flotation agent for ore dressing, and as desulfurizing agent for steel making and antimony refining. It is used as water softener in printing and dyeing industry. In tanning industry, it is used for degreasing raw leather, neutralizing chrome tanned leather and improving the alkalinity of chrome tanning solution. It is also used in the production of synthetic detergent additives such as sodium tripolyphosphate and other sodium phosphate salts.

Forbidden substancesStrong acid, aluminum, fluorine

Health hazardsThis product is irritating and corrosive. Direct contact can cause skin and eye burns. Inhalation of its dust and fumes in production can cause respiratory irritation and conjunctivitis, but also nasal mucosal ulceration, atrophy and nasal septum perforation. Prolonged exposure to the product solution can occur eczema, dermatitis, corns-like ulcers and skin laxity. The incidence of respiratory organ disease is elevated in workers exposed to the product. Accidental ingestion can cause burns in the digestive tract, mucous membrane erosion, bleeding and shock.

Toxicological information

LD50: 4090 mg/kg (rat oral)

LC50: 2300 mg/m3, 2 hours (rat inhalation)

Inflammation and explosion hazardsThis product is non-combustible, corrosive, irritating, and can cause burns to humans.

First Aid Measures

Skin Contact: Immediately remove contaminated clothing and rinse with plenty of running water for at least 15 minutes. Seek medical attention.

EYE CONTACT: Immediately lift eyelids and flush thoroughly with plenty of running water or saline for at least 15 minutes. Seek medical attention.

Inhalation: Remove from scene to fresh air. If breathing is difficult, administer oxygen. Seek medical attention.

Inhalation: Rinse mouth with water and give milk or egg white. Seek medical attention.

Fire Fighting Measures

Hazardous Characteristics: Corrosive. No specific combustion or explosion characteristics.

Hazardous Combustion Products: Natural decomposition products unknown.

FIRE FIGHTING METHODS: Firefighters must wear full body acid and alkali resistant firefighting clothing. When extinguishing the fire, move the container from the fire to an open area if possible.

Leak Emergency Response Isolate the leaking contaminated area and restrict access. Emergency response personnel are advised to wear dust masks (full face masks) and hazmat suits. Avoid dust, carefully sweep up and place in a bag to transfer to a safe place. If a large number of leaks, cover with plastic sheeting and canvas. Collect and recycle or transport to waste disposal place for disposal.

Operating precautions closed operation, strengthen ventilation. Operators must be specially trained and strictly follow the operating procedures. It is recommended that operators wear self-absorbing filtering dust masks, chemical safety glasses, anti-poison penetration coveralls and rubber gloves. Avoid generating dust. Avoid contact with acids. Load and unload lightly when handling to prevent damage to packaging and containers. Equip with emergency response equipment for leakage. Emptied containers may retain hazardous materials. When diluting or preparing solutions, add alkali to water to avoid boiling and splashing.

Storage PrecautionsStore in a cool, ventilated warehouse. Keep away from fire and heat source. It should be stored separately from acids, etc. Do not mix storage. The storage area should be equipped with suitable materials to shelter the leakage.

Transportation precautionsPackaging should be complete and loading should be stable. During transportation, make sure the container does not leak, collapse, fall or get damaged. It is strictly prohibited to mix and transport with acid and edible chemicals. During transportation, it should be protected from exposure to sunlight, rain and high temperature. Vehicles should be thoroughly cleaned after transportation.

Educational points of middle school generally require mastery of the common name of sodium carbonate, the main purpose, chemical formula and some common reactions (such as Na2CO3 + BaCl2 = 2NaCl + BaCO3 ↓, etc.

NaHCO3

Open Classification: Science

Sodium bicarbonate

Molecular formula: NaHCO3