Knowledge Bank

The methods of Knudsen's free flow and matrix isolation have been applied to the study gaseous species in equilibrium with crystalline $NH4ClO4$. The gaseous species effusing from a cell at $200\circ C$ have been successfully trapped at liquid He temperature in a $N2$ matrix. The infrared spectra of these species have been observed in the region $4000-650cm-1$. The spectra show that the only major species present in the vapor are $NH3$ and $HClO4$ in the temperature range studied $(150-200\circ C)$. Thus, contrary to proposals found in the literature$\mathrm{<mrow\; data-mjx-texclass="ORD">1,2</mrow>}.NH4ClO4$ does sublime by first dissociating into $NH3$ and $HClO4$.