Question

Hi guys,

The questions says: "A single-patient hyperbaric chamber has a volume of 640 L. At a temperature of 26 ∘C, how many grams of oxygen are needed to give a pressure of 1.9 atm?" It wants it up to 2 significant figures.
I did the problem a couple of times and it came up wrong. I'm not sure what I did wrong but any help would be appreciated.

Answer 1

1587.2 g

Step-by-step explanation:

First of all, we need to calculate the number of moles of oxygen. We can do it by using the equation of state for an ideal gas:

`pV=nRT`

where in this case:

`p=1.9 atm` is the pressure of the gas

V = 640 L is the volume

n is the number of moles

`R=0.082 atm L mol^(-1) K^(-1)` is the gas constant

`T=26^(\circ)C+273=299 K` is the absolute temperature of the gas

Solving for n, we find:

`n=(pV)/(RT)=((1.9)(640))/((0.082)(299))=49.6 mol`

Now we can find the mass of the oxygen by using the formula:

`m=nM`

where:

n = 49.6 mol is the number of moles

M = 32 g/mol is the molar mass of molecular oxygen

Therefore, substituting,

`m=(49.6)(32)=1587.2 g`