# Thermodynamics

posted by .

A 12 cu.ft tank contains hydrogen sulfide gas at 150psia & 80°F after 5 pounds of the gas have been drawn out. Before any gas left the tank the temperature was 70°F.

What mass of gas was in the tank originally and what pressure?

just to check:
R=45.2
V=12cu.ft = 20736cu.in
t=80°f = 540°R

m=(PV)/(RT)
m=(150 x 20736 x (1/12)) / (45.5 x 540)
m=10.6195

original mass inside the tank
10.6195+5=15.6195lb

original pressure
P=(mRT)/V
P=(15.6195 x 45.2 x 530) / (20736 x (1/12))
P= 216.5398

• Thermodynamics -

Your method looks OK but I would have to check the value of R in such unconventional units. I don't understand whay you multiplied V by 1/12 instead of 12

• Thermodynamics -

My mistake I forgot to add the units

Unit of R = (ft lb(force)) / lb(mass) °R

P = lb x (ft lb(force)) / lb(mass) °R) / (cu in x (1ft/12in)

the (1ft/12in) is suppose to make the P into lb / sq in.

• Thermodynamics -

Edit:

P = lb x (ft lb(force)) / lb(mass) °R) °R / (cu in x (1ft/12in)

• Thermodynamics -

If you were converting cubic inches to cubic feet, you would multiply by 1/1728, not 1/12.

## Similar Questions

1. ### physics

a metal tank with a volume of 3.10 L will burst if the absolute pressure of the gas exceeds 100 atm. If 11 mol of an ideal gas is put into the tank at a temperature of 23.0 C, to what temperature can the gas be warmed before the tank …
2. ### Physics

A metal tank with volume 3.10 L will burst if the pressure of the gas it contains exceeds 100 atm. (a) If 11.0 mol of an ideal gas is put into the tank at a temperature of 23.00C, to what temperature can the gas be warmed before the …
3. ### Physics

A rigid tank contains 1.80 moles of an ideal gas. Determine the number of moles of gas that must be withdrawn from the tank to lower the pressure of the gas from 27.9 atm to 4.80 atm. Assume the volume of the tank and the temperature …
4. ### Physics

A rigid tank contains 1.20 moles of an ideal gas. Determine the number of moles of gas that must be withdrawn from the tank to lower the pressure of the gas from 28.5 atm to 5.30 atm. Assume the volume of the tank and the temperature …
5. ### algebra

while driving a car you realize that you only have one eighth gas remaining before you run out of gas you pull into a gas station and put is gallons of gas in your car's tank is now three fourths full how many gallons of gas does your …
6. ### physics

Question Part Points Submissions Used 1 –/1 0/2 Total –/1 A rigid tank contains 1.40 moles of an ideal gas. Determine the number of moles of gas that must be withdrawn from the tank to lower the pressure of the gas from 21.6 atm …
7. ### science

'Imagine there is a tank of unknown gas that contains 53.31% carbon, 11.18% hydrogen, and 35.51% oxygen by mass. At 35.0 °C and 0.455 bar, 2.00 L of the gas has a mass of 3.20 g. Using this information, answer the following questions. …
8. ### physics

A rigid tank contains 1.80 moles of an ideal gas. Determine the number of moles of gas that must be withdrawn from the tank to lower the pressure of the gas from 21.6 atm to 5.80 atm. Assume the volume of the tank and the temperature …
9. ### algerbra

how to set up this problem? your new car's gas tank holds 12 gallons of gas, and you get 45miles/gallon. you travel 35miles and run out of gas. how much gas was in your tank when you left?
10. ### Chemistry

Propane gas is stored in a tank at a pressure of 15.0 atm at 22.0 °C. The tank can hold a pressure of 42.0 atm before bursting. During a fire the gas is heated to 600.0 °C. What is the gas pressure, and will the tank contain the …

More Similar Questions