Натрия селенит химические свойства, назначение, производство
Химические свойства
Sodium selenite is a white crystalline substance.
Использование
Sodium selenite Na2O3Se is used in the production of red enamels and in the manufacture of clear red glass.
Определение
ChEBI: An inorganic sodium salt composed of sodium and selenite ions in a 2:1 ratio.
Общее описание
A white colored crystalline solid. Soluble in water and more dense than water. Contact may irritate skin, eyes and mucous membranes. Toxic by ingestion, inhalation and skin absorption.
Реакции воздуха и воды
Soluble in water.
Профиль реактивности
Sodium selenite is incompatible with strong acids.
Опасность
Toxic by ingestion.
Угроза здоровью
Toxic by ingestion. In humans, a concentration of 5 ppm in food or 0.5 ppm in milk or water has been estimated to be dangerous. Elemental selenium has low acute systemic toxicity, but dust or fumes can cause serious irritation of the respiratory tract.
Пожароопасность
May burn but will not ignite readily. When heated to decomposition, may emit toxic fumes of selenium and sodium oxide. Stable in air.
Профиль безопасности
Poison by ingestion, intraperitoneal, intravenous, subcutaneous, intracervical, parenteral, and intramuscular routes. Experimental teratogenic and reproductive effects. Questionable carcinogen. Human mutation data reported. When heated to decomposition it emits toxic fumes of Se and Na2O. See also SELENIUM COMPOUNDS.
Возможный контакт
Sodium selenite is used in glass manufacturing and as an alkaloidal reagent; for removing green color from glass during its manufacture; alkaloidal reagent; reagent in bacteriology; testing germination of seeds; decorating porcelain; as a livestock feed additive.
Перевозки
UN2630 Selenates or Selenites, Hazard Class: 6.1; Labels: 6.1-Poisonous materials.
Методы очистки
Crystallise sodium selenite from a saturated aqueous solution where its solubility is 68% at 20o to give the pentahydrate salt. This yields the anhydrous salt on heating at 40o. [Fehér in Handbook of Preparative Inorganic Chemistry (Ed. Brauer) Academic Press Vol I p 431 1963].
Несовместимости
The aqueous solution is a medium strong base. Reacts with water, strong acids; hot surfaces; causing decomposition and a toxic hazard.
Утилизация отходов
Liquid or solid: make a strongly acidic solution using hydrochloric acid. Slowly add sodium sulfite to the cold solution. Stir mixture producing sulfur dioxide. Heat, forming dark-gray selenium and black tellurium. Let stand overnight. Filter and dry. Ship to supplier.
Натрия селенит препаратная продукция и сырье
сырьё
препарат