Is HNO2 ionic or molecular

Answer 1

Nitrous acid HNO2 cannot be isolated as a pure compound. In the gas phase molecules of HNO2 are covalently bonded. In water it is a weak acid forming the nitrite ion however it readily disproportionates:-

3HNO2 -> H3O+ + NO3- + NO

Answer 2

HNO2 is a molecular compound because it is composed of covalent bonds between nitrogen and oxygen atoms. It does not dissociate into ions when dissolved in water.