Mole conept: Calculate the follwing in `48g` of oxygen gas (diaxygen) at room temperature `(25^(@) C)`: (i) moles of `O_(2)`, (Ii) number of `O_(2)` molecules, (iii) number of `O` atoms, and (iv) number of electrons.
Strategy: The molecular mass of dioxygen `(O_(2))` is `32 mu`Thus, its molar mass is `32.0g mol^(-1)`, Now, use the needed information:
(a) one mole of `O_(2)` contains Avogadro's number of `O_(2)` molecules,
(b) one `O_(2)` molecules contains 2 oxygen atons, and `(c)` one oxygen atom contains 8 electrons.

Explanation

(i) Moles fo `O_(2)` =
`= ("Mass of" O_(2))/("Molar mass of" O_(2)) = (48 g)/(32 "g mol"^(-1)) = 1.5 mol O_(2)`
(ii) Number of `O_(2)` molecules
= (Moles of `O_(2)`) (Avogadro's constant)
`= (1.5 "mol") (0.022xx10^(23) "molecules mol"^(-1))`
`= 9.033xx10^(23) O_(2)` molecules
(iii) Number of `O` atoms
= Number of `O_(2)` molecules)
`xx` (Oxygen atoms per `O_(2)` molecules)
`= (9.033xx10^(23) "molecules") ("2 atoms molecule"^(-1))`
`= 1.807xx10^(24) O` atoms
(iv) Number fo electrons
= Number of `O` atoms) `xx` (Electrons per `O` atom)
`= (1.807xx10^(24)` atoms) (8 electrons `atom^(-1)`
`= 1.445xx10^(25)` electrons