In which of the following minimum amount of `O_(2)` is required per gram of reactant

Options

A. `4Fe(s) + 3O_(2)(g) rarr 2Fe_(2)O_(3)(s)`
B. `2M g(s) + O_(2)(g) rarr 2Mg O(s)`
C. `P_(4)(s) + 5O_(2)(g) rarr P_(4)O_(10)(s)`
D. `C_(3)H_(8)(g) + 5O_(2)(g) rarr 3CO_(2)(g) + 4H_(2)O (l)`

Answer

A

Explanation

`4Fe(s) + 3O_(2)(g) rarr 2Fe_(2)O_(3)(g)`
No. of moles of `O_(2)` required for one gram of `Fe = (3)/(224)` moles, `2Mg(s) + O_(2)(g) rarr 2MgO(s)`
No. of moles of `O_(2)` required for one gram of Mg `Mg = (1)/(48)` moles, `P_(4(s)) + 5O_(2) rarr P_(4)O_(10(s))`
No. of moles of `O_(2)` required for one gram of `P_(4) = (5)/(124)` moles
`C_(3)H_(9)(g) + 5O_(2)(g) rarr 3CO_(2) (g) + 4H_(2)O (l)`
No. of moles of `O_(2)` required for one gram of `C_(3)H_(8) = (5)/(44)` moles
So least amount is needs for the first reaction and is equal to `(3)/(44)` moles