Which of the following information is correct with respect to group 15 elements and their compounds

Colourless gas is produced when concentrated $HN{O}_3$ reacts with Zn and Cu

White phosphorous on reaction with alkali gives of hypo phosphorous acid where as red phosphorous on heating with alkali gives of hypo phosphoric acid

Phosphorous acid on heating disproportionate to give phosphoric acid and hypo phosphorous acid

N – N bond length in $N_2{O}_3 and N_2{O}_4$ are almost comparable