Physics
posted by Gabe .
The boiling point of helium at 1 atm is 4.2 K.
What is the volume occupied by helium gas
due to evaporation of 70 g of liquid helium at
1 atm pressure and a temperature of 6.2 K?

Physics 
bobpursley
This is not a trivial question. At those temperatures, the ideal gas law does not apply. Additionally, there are intermolecular forces that "compress" the volume.
Here is an estimate. The density of liquid helium is about .125g/ml, so 70 grams occupies about .560Liters (appx) as a liquid.
So this volume is the starting point, as is 4.2K as the "absolute" zero for the gas.
Now we fiddle with the Gas law:
PV=nRT
P(V+.560)=nR(6.24.2)
1(V+.560)=70/4.003 * 0.082057*2
V=2.31 liters
check this . Remember, this calculation is a stretch at low temps. 
Physics 
drwls
There are various nonideal forms of the gas law that take into account molecular sizes and intermolecular attraction.
One of them is called the van der Waals equation. You have not been provided with the two constant paramters (a and b) that are needed to use that equation. The other is called the law of corresponding states, if I recall correctly. Temperatures are referred to the boiling point are part of the equation. I suspect that is what you need to take a look at to answer the question. Your reading assignment should provide a clue of wh8ch equation to use. 
Physics 
drwls
This may help. It describes a way of using critical point properties to apply the Van der Waals equation of state:
http://www.phys.uri.edu/~gerhard/PHY525/tln30.pdf
Respond to this Question
Similar Questions

Chemistry  Gas Laws
Liquid helium at 4.2 K has a density of 0.147 g/mL. Suppose that a 1.00L 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 … 
chemistry
A heliumfilled balloon of the type used in longdistance flying contains 420,000 ft3 (1.2 times 107 L) of helium. Suppose you fill the balloon with helium on the ground, where the pressure is 737 mm Hg and the temperature is 16.0 … 
chem
A spherical glass container of unknown volume contains helium gas at 25°C and 1.950 atm. When a portion of the helium is withdrawn and adjusted to 1.00 atm at 23°C, it is found to have a volume of 1.55 cm3. The gas remaining in the … 
chem
A spherical glass container of unknown volume contains helium gas at 25°C and 1.950 atm. When a portion of the helium is withdrawn and adjusted to 1.00 atm at 23°C, it is found to have a volume of 1.55 cm3. The gas remaining in the … 
chem
A balloon filled with 22.3 mol helium has a volume of 500. L at 0.0°C and 1.00 atm pressure. The temperature of the balloon is increased to 38.0°C as it expands to a volume of 570. L, the pressure remaining constant. Calculate q, … 
chem
A balloon filled with 22.3 mol helium has a volume of 500. L at 0.0°C and 1.00 atm pressure. The temperature of the balloon is increased to 38.0°C as it expands to a volume of 570. L, the pressure remaining constant. Calculate q, … 
Physics
The boiling point of the helium at i atm is 4.2 k, what is the volume occupied by the helium gas due to evaporation of 30 g of liquid at 1 atm pressure and a temperature of 5.2 k. Answer in L 
physics
A rigid tank contains 38:0 kg of O2 gas at a pressure of 9:70 atm. If the oxygen is replaced by helium, how many kilogram of helium will be needed to produce a pressure of 8:00 atm? 
Chemistry
A cylinder containing 15.0 L of helium gas at a pressure of 165 atm is to be used to fill party balloons. Each balloon must be filled to a volume of 2.0 L at a pressure of 1.1 atm. What is the maximum number of balloons that can be … 
Science
A helium tank has a volume of 8.0 L. It contains enough helium to fill 23 circular balloons with a radius of 15 cm at a temperature of 25.0 C (room temperature). Assume that the pressure inside the balloons is 2.0 atm. What volume …