Question

Which would contain 9.03 × 10^23 oxygen atoms? A) 0.25 mol aluminium oxide B) 0.75 mol sulfur dioxide C) 1.5 mol sulfur trioxide D) 3.0 mol water

Answer 1

Well one mole of stuff specifies `6.022xx10^23` individual items of stuff.....

Explanation:

But of course we must specify the item. In the first scenario we gots `0.25*mol` `"aluminium oxide"`, i.e. `Al_2O_3`..approx. `4.5xx10^23*"oxygen atoms"`...

And in the second scenario we gots `6.022xx10^23*mol^-1xx2xx0.75*mol` `"oxygen atoms"=9.0xx10^23*"oxygen atoms"`. So it looks like scenario 2 is the winner. And scenario 3 and 4 contain too many oxygen atoms to fulfil your given criterion.

Answer 2

`B`

Explanation:

`0.75` mol sulphur dioxide = `0.75` mol of sulphur `+1.5` mol of oxide

`1.5` mol = `1.5 * 6.02 * 10^23 = 9.03*10^23`

`1.5` mol of oxide = `0.75` mol dioxide = `9.03*10^23` oxygen atoms