Question

Oxygen has a density of 1.43 g/l at stp. what is the density of oxygen at 1.30 atm?

Answer 1

At STP means Pressure= 1 atm and Temp= 273K

Density= mass/volume=grams/L
M= molar mass
P= pressure
R= gas constant
T= temp

Density= PM/RT

Density= (1.30 atm x 32 grams/mol)/(0.0821 x 273K)= 1.86 g/L

Answer 2

Explanation:

It is given that pressure is 1.30 atm.

So, at STP temperature will be 273.15 K. And, according to the ideal gas equation:

                         PV = nRT ........ (1)

And,    Density = $\frac{mass}{volume}$

or,               Volume = $\frac{mass}{Density}$ ....... (2)

Putting equation (2) is equation (1) we get the following.

                                 PV = nRT

             $P \times \frac{mass}{Density} = nRT$

Molar mass of oxygen is 32 g/mol. Now, putting the given values into the above equation to calculate density as follows.

              $P \times \frac{mass}{Density} = nRT$

               $1.30 \times \frac{32 g/mol}{Density} = 1 \times 0.0821 L atm/mol K \times 273.15 K$      

                    Density =  $\frac{41.6}{22.42}$ g/L

                                  = 1.855 g/L

Thus, we can conclude that density of oxygen at 1.30 atm is 1.855 g/L.