How many moles of magnesium phosphate, `Mg_3(PO_4)_2` , will contain 0.25 mole of oxygen atoms ?

Options

A. `3.125 xx 10^(-2)`
B. `1.25 xx 10^(-2)`
C. `2.5 xx 10^(-2)`
D. `0.02 `

Answer

A

Explanation

From the molecular formula of `Mg_3(PO_4)_2` .it is clear that 1 mole of `Mg_3(PO_4)_2` contains 8 mole of O atoms .
8 mole of O atoms = 1 mole of `Mg_3 (PO_4)_2 ` 0.25 mole of O atoms ` = 1/8 xx 0.25 ` mole of `Mg_3 (PO_4)_2 = 3.125 xx 10^(-2)`