Pertechnetic acid
Pertechnetic acid (HTcO4) is a compound of technetium that is produced by reacting technetium(VII) oxide (Tc2O7) with water or oxidizing acids, such as nitric acid, concentrated sulfuric acid, aqua regia, or a mixture of nitric and hydrochloric acids.[1] The resulting dark red, hygroscopic (water attracting) substance is a strong acid and easily donates protons.[2] In the concentrated sulfuric acid Tc(VII)tetraoxidotechnetate (pertechnetate) anion is unstable and undergo conversion to octahedral form of technetic(VII) acid TcO3(OH)(H2O)2 [30]
References