An unknоwn mаss оf аmmоnium perchlorаte, NH4ClO4 (117.5 g/mol), is placed in an evacuated 1.00 L flask and heated to 251°C. At this temperature the NH4ClO4 decomposes violently. The gaseous products exert a pressure of 466 mm Hg at 251°C. What mass of NH4ClO4 was placed in the flask?2NH4ClO4(s) → N2(g) + Cl2(g) + 2O2(g) + 4H2O(g)