A - 3.125 x 10 -2
B - 1.25 x 10 -2
C - 2.5 x 10 -2
D - 2 x 10 -2
Answer
A - 3.125 x 10 -2
Explanation:
In one molecule of Mg 3 (PO 4 ) 2 there are 8 Oxygen atoms
So in 1 mole of Mg 3 (PO 4 ) 2 molecules , there will be 8 moles of Oxygen atoms.
1 mole of Mg 3 (PO 4 ) 2 → 8 moles of O atoms
X → 0.25 moles of O atoms
Cross multiplying,
0.25 x 1 = 8X
X = 0.25/8
X = 3.125 x 10 -2
3.125 x 10
-2
moles of Magnesium Phosphate will contain 0.25 mole of oxygen atoms.