The heating of \( \mathrm{NH_4NO_2} \) at \( 60\text{–}70^\circ\mathrm{C} \) and \( \mathrm{NH_4NO_3} \) at \( 200\text{–}250^\circ\mathrm{C} \) is associated with the formation of nitrogen containing compounds \( X \) and \( Y \), respectively. \( X \) and \( Y \), respectively, are:
