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.

  1. Class 9
  2. Chapter 3 Class 9 - Atoms And Molecules (Term 2)

About the Author

CA Maninder Singh's photo - Founder at Teachoo
CA Maninder Singh
CA Maninder Singh is a Chartered Accountant for the past 11 years and a teacher from the past 11 years. He teaches Science, Accounts and English at Teachoo