anhydride sulfurique

Domaine: chimiechimie minérale
Date: 1983

Définition :

Prismes blancs, transparents; fumant à l'air. Trimorphe à l'état solide.

Note :

Emplois : agent de sulfonation :, matières colorantes; acide sulfurique fumant.

Terme :

anhydride sulfurique n. m.

Terme associé :

trioxyde de soufre n. m.

Traductions

anglais
Date : 1983
Définition

A toxic, irritating liquid in three forms ((...)); a strong oxidizing agent and fire hazard; used for sulfonation of organic chemicals.

An oxide of sulfur. In the solid state it exists in at least three forms, only one of which is stable, the other two being slowly converted into this from. Liquid sulfur trioxide boils at 44.5 °C. All forms of sulfur trioxide are extremely reactive, corrosive, and poisonous; they react with water to form sulfuric acid and at high temperatures dissociate into sulfur dioxide and oxygen.

Note :

When fuels burned at high temperatures (e.g., in industrial furnaces) some 5% of the sulfur appears in the stack gases as the gaseous trioxide, but when temperature drops this combines with water vapour to produce sulfuric acid mist. Sulfur trioxide does not exist as such in the atmosphere owing to the moisture that is always present. When data are given for atmospheric concentrations of sulfur trioxide they should be taken to mean concentrations of sulfuric acid expressed as sulfur trioxide for convenience.

Termes :
1. sulfur trioxide
2. sulphuric anhydride