Okay, just to make sure I've got it right, the next problem is this:
(using the same equation 2 NO + O2 -> 2 NO2)
How many molecules of O2 are needed to make 3.76 x 10^22 molecules NO2?
Would it be like this:
[math]\frac{3.76 \times 10^{22} \mbox{molecules NO2}}{1} \times \frac{1 \mbox{mol}}{6.022 \times 10^{23} \mbox{molecules NO2}} \times \frac{34.014 \mbox{g NO2}}{1 \mbox{mol}} \times \frac{1\times 31.998 \mbox{g O2}}{2 \times 34.014 \mbox{g NO2}} \times [/math] (same problem, just too long to fit in one [math ])
[math]\frac{1 \mbox{mol}}{31.998 \mbox{g}} \times \frac{6.022 \times 10 ^ {23} \mbox{molecules O2}}{1 \mbox{mol}}[/math]
And I know that is overly complicated and almost everything cancels out, but I was only taught one way to do this. I will simplify how I do it later - all I want to know is if that is one way of getting the correct answer.
So the molecules NO2 would cancel, the mol would cancel, the 34.014g NO2 would cancel, the 31.998 g would cancel, the mol would cancel, and the 6.022 x 10^23 would cancel. Leaving:
[math]\frac{3.76 \times 10^{22} \mbox{molecules}}{2}[/math]
Which is [math]1.88 \times 10^{22} \mbox{molecules O2}[/math], right?
EDIT: PS, I hope you don't mind that I used your post above to learn how to use the LaTeX, Cap'n Refsmmat.
EDIT, again: Oh, I see how I could have simplified the entire equation. I only had ten minutes to learn how to do this chapter and another, so I only learned how to apply the coefficients by grams. Duh, looking back, I could have saved myself a lot of work if I had realized it worked with molecules as well. Oh well, it took so long to write that, I think I'll leave it.