1. The problem statement, all variables and given/known data Au shaped tube has a total length of 1 m, it is initially filled with air at 20* C and 1 atm, mercury is poured in without letting air escape, compressing the air. This continues until the mercury is filled to a level L, how long is L 2. Relevant equations Im guessing PV=NRT, It seems like it should involve the density of HG but its not given, nor is the volume 3. The attempt at a solution I don't even know where to start, It seems like the final pressure is needed, Any suggestions?