Problem page calculate the mass of diphosphorus pentoxide p2o5 that contains a billion ×1.000109 oxygen atoms. be sure your answer has a unit symbol if necessary, and round it to 4 significant digits.

               4.71 × 10⁻¹⁴ g

Solution:

                 As we know,

             141.93 g (1 mole) P₂O₅ contains = 6.022 × 10²³ (5) O atoms

Or,

              141.93 g (1 mole) P₂O₅ contains = 3.011 × 10²⁴ O atoms

Therefore, we can say,

              3.011 × 10²⁴ O atoms are contained by = 141.93 g of P₂O₅

So,

              1.0 × 10⁹ (1 billion) O atoms will be contained by = X g of P₂O₅

Solving for X,

                       X = (1.0 × 10⁹ × 141.93 g) / 3.011 × 10²⁴

                       X = 4.71 × 10⁻¹⁴ g