How Does Temperature Affect Gas Pressure in a Sealed Container?

[mhn745]

Homework Statement

1) Liquid helium at 4.2 K has a density of 0.147 g/mL. Suppose that a 2.50-L metal bottle that contains air at 105K and 2.0 atm pressure is sealed off. If we inject 100.0 mL of liquid helium and allow the entire system to warm to room temperature (25 °C), what is the pressure inside the bottle?

2) A mouse is placed in a sealed chamber with air at 752.0 torr. This chamber is equipped with enough solid KOH to absorb any CO2 and H2O produced by the mouse. The gas volume in this chamber is measured to be exactly 2.30 L, and the temperature is held constant at 296K.
After two hours the pressure inside the chamber falls to 723.2 torr. What mass of oxygen has the mouse consumed?

 

[Borek]

PV=nRT

Show what you did.

 

[grapejellypie]

For the second problem, you are going to have to know the molarity of oxygen, so that you can find the original amount of O2 (grams) in the 2.30 L of O2. After you know the grams of O2, you can figure out the "n." Then, use PV=nRT, to calculate the new "n." By subtracting the new "n" from the old "n," and converting that molar value into grams, you get your answer.

 

[Borek]

For the second problem, you are going to have to know the molarity of oxygen, so that you can find the original amount of O2 (grams) in the 2.30 L of O2.

Not sure what you mean by "molarity" of oxygen, but you don't have to know it. Think about stoichiometry O₂ -> CO₂.

 

[GCT]

Homework Statement

1) Liquid helium at 4.2 K has a density of 0.147 g/mL. Suppose that a 2.50-L metal bottle that contains air at 105K and 2.0 atm pressure is sealed off. If we inject 100.0 mL of liquid helium and allow the entire system to warm to room temperature (25 °C), what is the pressure inside the bottle?

2) A mouse is placed in a sealed chamber with air at 752.0 torr. This chamber is equipped with enough solid KOH to absorb any CO2 and H2O produced by the mouse. The gas volume in this chamber is measured to be exactly 2.30 L, and the temperature is held constant at 296K.
After two hours the pressure inside the chamber falls to 723.2 torr. What mass of oxygen has the mouse consumed?

You had already posted the first problem ... what's the textbook answer?