Question #648a7

1 Answer
Jan 10, 2018

Either #1.5 * 10^23# #"atoms of oxygen"#, or #1.5 * 10^23# #"molecules of oxygen gas"#.

Explanation:

If there are 0.25 moles of oxygen atoms:
One mole of anything is #6.022*10^23# items of that thing.

The same applies for oxygen atoms! :)
And, if one mole of oxygen is #6.022*10^23# atoms, then #0.25# moles is:

#0.25*(6.022*10^23)=1.5 * 10^23# #"atoms"#.

If there are 0.25 moles of oxygen gas, or #O_2#:
Similarly, if one mole of oxygen gas (#O_2#) is #6.022*10^23# molecules, then #0.25# moles is #1.5 * 10^23# #"molecules"#.

This means there are #2*(1.5 * 10^23)=3.0*10^23# #"atoms"# of oxygen.