Chemistry
posted by Miley .
At a deepsea station that iss 200. m below the surface of the Pacific Ocean, workeres live in a highly pressurized enviornmetn. how many liters of gas at STP must be compressed on the surface to fill the underwater enviorment wiht 2.00*10^7 L of gast a 20.0 atm? Assume that temperature reamins constant. I did this problem using v1p1=v2p2. and got 400,000,000L. I know that is totally wrong, so can someone please help me with this problem! Thanks:)

well, in round terms, every ten meters adds one atmospher, so 200 meters is about 21 atmosphers, so volume should be increased by a factor of 21 (about).
P1V1=P2V2 is correct, but you need barometric pressure in meters of water. That would be .76*13.2 meters (the 13.2 is the density of mercury) or 10.03m
The pressure at 200 m is 200mwater+atmospheric, or 210mwater
Your problem states that the pressure is 20.0 atm, but that does not include atmospheric pressure above the ocean, it is pressing down also.
10.03*V=210*2E7liter
solve for V . Just looking, your answer is not far off. 
Oops, the density of mercury is 13.6, so atmospheric pressure is 10.34 meters water
This means pressure at 200 m is 200m+10.3m, which changes the final answer slightly.