• question_answer Which is the anhydride of $HN{{O}_{3}}$ out of ${{N}_{2}}O,\,NO$ and ${{N}_{2}}{{O}_{5}}$?

${{N}_{2}}{{O}_{5}}$ is the anhydride of $HN{{O}_{3}}$ and is formed as: $2HN{{O}_{3}}\xrightarrow{\,}\,{{N}_{2}}{{O}_{5}}+{{H}_{2}}O$.