Reaction of phenol with dil. `HNO_(3)` gives

Phenol on treatment with dil. HNO_(3) gives two products P and Q. P is steam volatile but Q is not , P and Q are respectively-

Iron is dropped in dil. HNO_(3) , it gives

Before the tests for halogens the Lassaigne's extract is to be boiled with dil. HNO_(3) - why?

Phenol on treatment with conc. HNO_(3) gives

Phenol on treatment with conc. HNO_(3) gives