How many moles of magnesium phosphate, `Mg_(3)(PO_(4))_(2)` will contain `0.25` mole of oxygen atoms?

Options

A. `2.5xx10^(-2)`
B. 0.02
C. `3.125xx10^(-2)`
D. `1.25xx10^(-2)`

Answer

C

Explanation

8 mole O contained by `to 1 "mole" Mg_(3)(PO(4)_(3))`
1 mole O contained `(1)/(8) "mole" Mg_(3)(PO(4)_(2))`
by
0.25 "mole" O is ` rArr (1)/(8)xx0.25` "mole" `Mg_(3)(PO(4))_(3)`
contained by ` = 3.125 xx10^(-2)` mole `Mg_(3)`