Where Did I Go Wrong in Calculating the Mass of Oxygen Using PV=nRT?

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SUMMARY

The discussion centers on calculating the mass of oxygen (O2) in a cylinder using the ideal gas law equation PV=nRT. The user initially calculated the number of moles (n) as 935499.4 using the provided pressure of 1.00e7 Pa, volume of 0.00260 m³, and temperature of 299 K. However, the user incorrectly multiplied the number of moles by Avogadro's number and an atomic mass unit conversion factor, leading to an erroneous mass calculation. The correct approach involves directly using the molecular weight of O2, which is 32 g/mol, to find the mass.

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  • Understanding of the ideal gas law (PV=nRT)
  • Knowledge of Avogadro's number (6.022e23)
  • Familiarity with molecular weight calculations
  • Basic principles of unit conversion in physics and chemistry
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  • Learn about molecular weight and its significance in stoichiometry
  • Study unit conversion techniques for mass and moles
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Homework Statement



In a portable oxygen system, the oxygen (O2) is contained in a cylinder whose volume is 0.00260 m3. A full cylinder has an absolute pressure of 1.00e7 Pa when the temperature is 299 K. Find the mass of oxygen in the cylinder.

Homework Equations


PV=nRT


The Attempt at a Solution


So first I solved for n in the PV=nRT eqn, (1.00e7)(.00260)/(8.31)(299K)= 935499.4 moles. After I obtained the Moles I multiplied by avadro's number (6.022e23) to get molecules, and than I multiplied by 1.6605e-27kg/atomic units to get mass. Aparently my answer is incorrect, where did I go wrong for solving this problem?


 
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What did you multiply by 1.6605e-27kg/atomic units to get mass? Also remember the molecular weight of O2 is 32.
 

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