Photochemical properties of tungstic acid

• Publisher: Elsevier Science
• Year: 1914
• Tongue: English
• Weight: 67 KB
• Volume: 177
• Category: Article
• ISSN: 0016-0032
• DOI: 10.1016/s0016-0032(14)90679-2

✦ Synopsis

In the presence of various reducing agents, e.g. cellulose, and under the influence of sunlight, tungstic acid undergoes change with formation of a blue color. According to Saban~ef, the action of hydrochloric acid on sodium tungstate gives, not colloidal tungstic acid, as Graham said, but sodium meta-tungstate: 4Na2WO, + 6HC1 = Na~O4WO 3 + 6NaC1 + 3H.~O. The author's investigations on the influence of sunlight in presence of dextrose on the initial product of this reaction indicates that this product, which is sensitive to light, is probably not sodium metatungstate. The initial product undergoes change into one which shows no photochemical properties at a velocity coresponding with the equation of a reaction of the first order; a rise of temperature causes the reverse change.