Question

How many oxygen molecules are needed to make a `3.43*g` mass of `SO_2`?

Answer 1

Approx. `6.4xx10^22` dioxygens......

Explanation:

We need a stoichiometric equation....

`S(s) + O_2(g) rarr SO_2(g)`, and I have ASSUMED combustion to give `SO_2` (`SO_3` is a little trickier!).

And thus there are equimolar quantities of dioxygen and sulfur.

`"Moles of sulfur"=(3.43*g)/(32.06*g*mol^-1)=0.107*mol`.

And thus we need `0.107*mol` dioxygen, and this represents a number of `0.107*molxx6.022xx10^23*mol^-1=6.44xx10^22` oxygen MOLECULES.....