1. The problem statement, all variables and given/known data Current vacuum technology can achieve a pressure of 1.0 x10-10mm of Hg. At this pressure, and at a temperature of 40.0 degrees C, how many molecules are in 4.00cm3? 2. Relevant equations p=nRT/V 3. The attempt at a solution I would attempt this but I don't see how mm of hg would be considered a pressure... Doesn't that mean millimeters of Mercury?? How is that considered a pressure? My book doesn't explain this. Shouldn't it be in pascal?