Molar mass P₂O₅ = 141.9445 g/mol
141.9445 g ------------- 6.02 x 10²³ molecules
0.230 g ------------------- ?
molecules = 0.230 * 6.02 x 10²³ / 141.9445
molecules = 1.3846 x 10²³ / 141.9445
= 9.75 x 10²⁰ / 141.9445
= 6.868 x 10¹⁸ molecules of P₂O₅
calculation of the total number of atoms
P₂O₅ = 2 atoms of P and 5 atoms of O = 2 + 5 = 7
1 molecule P₂O₅ -------------------- 7 atoms
6.868 x 10¹⁸ molecules ------------ ?
atoms = 6.868 x 10¹⁸ * 7 / 1
= 4.807 x 10¹⁹ atoms
hope this helps!
