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.

1587.2 g

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:

where in this case:

is the pressure of the gas

V = 640 L is the volume

n is the number of moles

is the gas constant

is the absolute temperature of the gas

Solving for n, we find:

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

where:

n = 49.6 mol is the number of moles

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

Therefore, substituting,

a electronegativity decreases beacuse the size of nucleus is bigger.