Posted by **Jay** on Friday, March 2, 2007 at 10:07am.

Liquid helium at 4.2 K has a density of 0.147 g/mL. Suppose that a 1.00-L metal bottle that contains air at 118K and 1.0 atm pressure is sealed off. If we inject 120.0 mL of liquid helium and allow the entire system to warm to room temperature (25 °C), what is the pressure inside the bottle?

Add the partial pressures of the air and that of the vaporized helium.

120 mL of LHe has a mass of 0.147 g/ml x 120 mL = 17.64 g. That is = 4.406 moles. From that and the volume and temperature, you can calculate the partial pressure of He, using

P = nRT/V

R = 8.205*10^-2 atm*L/mole K

P(He)= 107.7 atm

The air partial pressure is much less. It starts out at 1.0 atm at 118K and rises to 1.0 x (298/118) = 2.5 atm at the higher temperature of 298 K.

Add the two partical pressures for the total pressure.

I don't guarantee my numbers, so check them yourself. The method should work.

thanks

## Answer this Question

## Related Questions

- chemistry - ind the partial pressure of oxygen in a sealed vessel that has a ...
- College Chemistry - 1. From data below, calculate the total heat (in J) ...
- College Chemistry - 1. From data below, calculate the total heat (in J) ...
- College Chemistry - 1. From data below, calculate the total heat (in J) ...
- Physics - The boiling point of helium at 1 atm is 4.2 K. What is the volume ...
- Chem hw! - 1. What pressure would be needed to compress 25.1 mL of hydrogen at 1...
- Chem hw! - 1. What pressure would be needed to compress 25.1 mL of hydrogen at 1...
- Physics - Useful Constants: 1 Torr = 133.32 Pa; R = 8.3145 J/mol·K You have a ...
- Chem 151 - The atmosphere in a sealed diving bell contained oxygen and helium. ...
- Chemistry - The output of a diesel generator, which contains a mixture of CO2 ...