[Jesse]

my professor gave us a question for extra credit that is due tomarrow, and i have tried and tried, but i just cant figure it out so here goes:  according to a guage on a tank, the pressure in the tank is 1000 lbs.  A volume of gas is removed from the tank and at 15 lbs. pressure, the volume is 1 cu. ft.  Whem this amount of gas was removed from the tank, the pressure in the tank dropped to 995 lbs.  What is the volume of the tank?

I thought i could use boyles law, but i dont know how to figure out the the V1, much less the V2.  is there anything else i can do?  

Please *delete me*

[Mitch]

I would start by first converting all the pressures that are listed in pounds to atmospheres and cuft to liters. And then use P1V1 = P2V2 for P1=15lb and P2=1atm and V1=1cuft and V2=?liters.

[Jesse]

Thanks i appreciate it bunches.  That helps a little but that second sentence in the problem is throwing me off.  

[Jesse]

i think i figured this out.  can someone check behind me to make sure?

P1V1=PrPr + P2V1   this was derived out of the ideal gas law solving for n.

soooo.....1000V1=15(1) + 995V1

5V1=15

V1=3 cu. ft.

does this sound about right?