Question

How many moles are in a sample of `CO_2` that contains `8.12*10^22` of `O` atoms?

Answer 1

0.067mols

Explanation:

`CO_2`

From the formula we can see that,

`2xx6.02xx10^(23)`atoms of `O` are in `6.02xx10^(23)` molecules of `CO_2`
`:. 1` atom of `O` is in `(6.02xx10^(23))/(2xx6.02xx10^(23))` molecules of `CO_2`
`:.8.12xx10^(22)` atoms of `O` are in `(6.02xx10^(23)xx8.12xx10^(22))/(2xx6.02xx10^(23))` molecules of `CO_2`

`=4.06xx10^(22)` molecules

we know,

`n=N/N_A`

`=(4.06xx10^(22))/(6.02xx10^(23))`

`=0.067mol s`