Question

Scuba Tanks: A popular scuba tank is the “aluminum 80,” so named because it can deliver 80 cubic feet of air at “normal” temperature (72°F) and pressure (1.00 atm, 14.7 psi) when filled with air at a pressure of 3000 psi. A particular aluminum 80 tank has a mass of 15 kg when empty. What is its mass when filled with air at 3000 psi?

Answer #1

V = 80 ft3 of T = 72F, P = 1 atm air at P = 3000 psi

m = 15 kg of empty

find mass when filled with air...

Apply Ideal Gas Law,

PV = nRT

where

P = absolute pressure

V = total volume of gas

n = moles of gas

T = absolute Temperature

R = ideal gas constant

PV = nRT

n = PV/(RT)

P = 3000 psi = 3000/14.7 = 204.081 atm

V = 80ft3 = 2265.35 Liters

T = 72F = 22°C = 22.2+273.15 K = 295.35 K

n = (1)(2265.35)/(0.082*295.35)

n = 93.537 mol of air

mass = mol*MW = 93.537*29 = 2712.573 g = 2.71 kg

Total mass = 15 + 2.71 = 17.71 kg of tank + air

A scuba diver takes a tank of air on a deep dive. The tank's
volume is 10 L and it is completely filled with air at an absolute
pressure of 237 atm at the start of the dive. The air temperature
at the surface is 85 ?F and the diver ends up in deep water at 60
?F.
Assuming thermal equilibrium and neglecting air loss, determine
the absolute internal pressure of the air when it is cold.

3. A scuba tank, when fully submerged, displaces 15.7 liters of
seawater. The tank has a total mass of 14 kg when empty; when full,
it contains 3 kg of air. a) If you release the full tank (from
rest) from a spot underneath the surface of the ocean, does it
sink, remain at that spot, or rise to the surface? Explain. b) If
the tank is initially 2 m below the ocean surface, determine the
pressure that the ocean...

4. The diver in Problem 2, while underwater at a depth of 20.0
m, breathes from the tank so that the air entering the diver’s
lungs is at the same pressure as that of the surrounding water. If
each breath fills the diver’s lungs to a volume of 3.70 L, and the
air he breathes warms to a temperature of 30.0OC, how many breaths
can the diver take before the air remaining in the tank drops to a
pressure of...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 47 seconds ago

asked 3 minutes ago

asked 3 minutes ago

asked 3 minutes ago

asked 4 minutes ago

asked 9 minutes ago

asked 15 minutes ago

asked 15 minutes ago

asked 15 minutes ago

asked 15 minutes ago

asked 18 minutes ago

asked 19 minutes ago