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

  • Thread starter Thread starter physics4u
  • Start date Start date
AI Thread Summary
The discussion revolves around calculating the mass of oxygen in a cylinder using the ideal gas law, PV=nRT. The user initially calculated the number of moles (n) as approximately 935,499.4 but incorrectly multiplied by Avogadro's number to find the number of molecules instead of directly converting moles to mass. The correct approach involves using the molecular weight of O2, which is 32 g/mol, to convert moles to grams. The error stems from not applying the molecular weight correctly in the final calculation. Clarifying the conversion from moles to mass using the molecular weight is essential for accurate results.
physics4u
Messages
3
Reaction score
0

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?


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

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Calculating Oxygen Mass in a Portable Cylinder | Physics Homework Help
Replies
2
Views
4K
Thermal efficiency of the engine in a PV diagram
Replies
2
Views
3K
Chemistry Where Did I Go Wrong in My Gas Law Calculation?
Replies
2
Views
2K
Moles of gas helium balloon; buoyancy; PV=nRT
Replies
3
Views
8K
How Do You Calculate the Mass of Oxygen in a Cylinder Using the Ideal Gas Law?
Replies
7
Views
2K
Mixture of hydrogen and oxygen in container
Replies
27
Views
4K
How to find the Angular Velocity?
Replies
16
Views
3K
Basic ideal gas PV=nRT question ( fast )
Replies
4
Views
16K
Calculating Mass and Height of Ideal Gas in a Vertical Tank
Replies
1
Views
3K
Carnot Engine cycle on PV Diagram
Replies
5
Views
2K

Hot Threads

Recent Insights

Back
Top