PbO is a base. It reacts with nitric acid and forms soluble lead nitrate
`PbO+2HNO_(3)tounderset("Soluble")(Pb(NO_(3))_(2))+H_(2)O" (acid base reaction)"`
Nitric acid does not react with `PbO_(2)`. Both of them are strong oxidising agents. In `HNO_(3)` nitrogen is in its maximum oxidation state(+5) and in `PbO_(2)`. leads is in its maximum oxidation state (+4). Therefore, no reaction takes place.
