Calculate density of Oxygen at STP

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SUMMARY

The density of oxygen at standard temperature and pressure (STP) can be calculated using the ideal gas law, represented by the equation PV=nRT. For oxygen (O2), the molar mass is 32 g/mol, and the appropriate gas constant R is 8.315 J/(mol·K). When substituting the correct values, including converting pressure from atm to pascals (1 atm = 101,325 Pa), the calculated density of oxygen at STP is 1.43 kg/m³. The initial calculation of 0.007 g/m³ was incorrect due to unit mismanagement and incorrect molar mass usage.

PREREQUISITES
  • Understanding of the ideal gas law (PV=nRT)
  • Knowledge of unit conversions (atm to pascals)
  • Familiarity with molar mass calculations (O2 = 32 g/mol)
  • Basic algebra for manipulating equations
NEXT STEPS
  • Learn about unit conversions in gas law calculations
  • Study the ideal gas constant and its various values
  • Explore the concept of molar mass and its significance in gas density calculations
  • Investigate common mistakes in applying the ideal gas law
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Chemistry students, educators, and anyone involved in gas law applications or density calculations will benefit from this discussion.

EroAlchemist
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Homework Statement


Calculate the density of Oxygen at STP using the ideal gas law


Homework Equations



PV=nRT

The Attempt at a Solution



n = (X grams Oxygen / 16g/mol Oxygen)
I set V = to 1 m3
P = 1 atm
R = 8.315 J/Mol K
T = 273 K

PV = nRT
PV/RT = n
1/(8.315*273) = X grams Oxygen / 16g/mol Oxygen
[1/(8.315*273)]*16 = X grams Oxygen
X = .007g/m3

Book answer is 1.43 kg/m3. I'm way off somewhere.
Thanks for any help!
 
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The SI unit of pressure is the pascal. 1 atm = 101,325 Pa. Try this in the equation and see what you get.
However I'm not sure about the *16 you got, you might want to look that up it doesn't seem right, but I can't remember how you work it out.
 
EroAlchemist said:
n = (X grams Oxygen / 16g/mol Oxygen)

Oxygen gas consist of O2molecules. The atomic weight of the oxygen atom is 16 g/mol. The molar weight of the oxygen gas is 32 g/mol.

ehild
 
As madmike already signaled - watch your units. There are plenty of possible R values to select for to fit units used for volume and pressure, the one you used requires you to use pressure in Pa.

Check out table in http://en.wikipedia.org/wiki/Ideal_gas_constant
 

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