Question

Calculate the total number of atom in 3.5g of P4

Answer 1

Number of moles = amount in g / molar mass

= 3.5 g/ 123.90 g/mol

= 0.0282 mole P4

1 mole P4 = 4 mole P  

1 mole = 6.022*10^23 atoms  

0.0282 mole  * 6.022 *10^23 atom s/ 1 mole  *4/1  

= 6.79*10^22 atoms