Selenic acid

Selenic acid is a chemical compound. It is an acid. Its chemical formula is H2SeO4. 

Properties
It is normally a colorless solution in water. It is a strong oxidizing agent. It can turn into selenium trioxide when dehydrated carefully. It is a very strong acid. It reacts with hydrochloric acid to make chlorine and selenous acid. It can dissolve gold to make gold selenate. When heated above 200°C, it releases oxygen and turns into selenous acid. It reacts with bases to make selenates.

Preparation
Selenic acid is made by oxidation of selenium dioxide with hydrogen peroxide. It is hard to evaporate it, but when it is evaporated, it makes colorless crystals. It can be made by oxidation of selenous acid with a strong oxidizing agent, such as potassium permanganate, chlorine, or bromine. The HCl and HBr made as a byproduct can reduce the selenic acic to selenous acid again, though, so it has to be taken out. 

It can also be made by reacting selenium with chlorine in water.

Related pages
Hydrogen selenide

Category:Oxoacids
Category:Selenium compounds