Relationship between Atomic PPM and Mole

[1question]

Homework Statement

Why does 25 atomic ppm oxygen mean 25 moles of oxygen in 1e6 mole Fe?

Homework Equations

# = mol*Avo

The Attempt at a Solution

I understand the ppm (parts per million) part. Hence why 25 ppm means 25:1e6. What I do not understand is how they go from atomic to moles...

The only way I can explain it is:

# = mol*Avo ---> Since Avogadro's number is a constant, the difference between # (atomic) and mol (moles) is just a given ratio (a number), thus you can use either... But then where is the conversion?...

 

[Borek]

Not sure what your question is. 25 ppm means 25 atoms per 10⁶ atoms, 25 dozens of atoms per 10⁶ dozens of atoms, 25 thousands of atoms per 10⁶ thousands of atoms, 25*123456789 of atoms per 10⁶*123456789 of atoms and so son. You can plug any number, including Avogadro's constant.

After all, mole is just an overgrown dozen.

 

[DrClaude]

After all, mole is just an overgrown dozen.

And to think I was impressed by a baker's dozen...

 

[1question]

Thanks Borek. So what you're saying is that as long as the ratio is held, the number can be anything (even mole)? I forgot that mole is simply a means of expressing the amount of a chemical substance... just like # of atoms. Whoops.

 

[Borek]

Thanks Borek. So what you're saying is that as long as the ratio is held, the number can be anything (even mole)?

Exactly.