Technetium: reactions of elements

Reaction of technetium with air

Technetium is less reactive to air than manganese, which is immediately above technetium in the periodic table. It is about as reactive as rhenium metal, which is immediately below technetium in the periodic table. As such it tarnishes only very slowly in moist air. In practice, technetium is often supplied as a powder or as a sponge, and in this form it is much more reactive. When heated with oxygen the result is technetium (VII) oxide, (techentium heptoxide, Tc2O7).

4Tc(s) + 7O2(g) → 2Tc2O7(s)

Reaction of technetium with water

Technetium does not react with water under normal conditions.

Reaction of technetium with the halogens

In similar fashion to rhenium, immediately below technetium in the periodic table, technetium is often supplied as a powder or as a sponge, and in this form it is quite more reactive. When heated with fluorine the result is a mixture of technetium (VI) fluoride, (technetium hexafluoride, TcF6) and technetium (VII) fluoride, (technetium heptafluoride, TcF7).

Tc(s) + 3F2(g) → TcF6(s)

2Tc(s) + 7F2(g) → 2TcF7(s)

Technetium metal does dissolve in warm bromine water.

Reaction of technetium with acids

In similar fashion to rhenium, immediately below technetium in the periodic table, technetium is insoluble in hydrochloric acid (HCl) and hydrofluoric acid (HF). It does dissolve in nitric acid, HNO3, or concentrated sulphuric acid, H2SO4, both of which are oxidizing, to form solutions of pertechnetic acid, HTcO4. In this form, the technetium is in the formal +7 oxidation state.

Reaction of technetium with bases

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