Question

What is the chemical formula potassium dioxonitrate (5)

Answer 1

For your information there is no such chemical as potassium dioxonitrate(5). Give me you reference for that name. Your text? Your teacher? Your friends? Help me stamp out these incorrectly named compounds. There is a potassium nitrite (KNO2) also correctly named potassium dioxidonitrate(IV) and I've see potassium dioxidooxidonitrogen. Although all of these names are acceptable by IUPAC, I think potassium nitrite is the most often used name for KNO2. That is most likely the compound you tried to name.

Answer 2

oops. Hit the wrong key.
potassium dioxidonitrate(IV) should be potassium dioxidonitrate(III)