Question

# 1)Calculate the number of molecules of the compound and the number of atoms of each of...

1)Calculate the number of molecules of the compound and the number of atoms of each of the elements in 3.98 moles of SO3 . ? molecules, ? atoms of S, ? atoms of O 2) Calculate the number of molecules of the compound and the number of atoms of each of the elements in 3.35 moles of P4O12. ? molecules, ?atoms of P, ? atoms of O

We are given moles of SO3

Number of molecules = moles x Avogadro number

Therefore

3.98*6.02 E23=2.39 E24 SO3 molecules

1 molecule of SO3 has 1 atom of S

Therefore number of atoms of S in 2.39E24 SO3 molecules contains

2.39 E24 SO3 molecule x 1 S atom / 1 SO3 molecule

=2.39 E24 S atom

1 molecule of SO3 has 3 atoms of O so

Number of atoms of O

2.39 E24*3/1=7.17 E24 O atoms.

2)

Number of molecules of P4O12

3.35*6.02E23=2.02 E24 P4O12 molecules

1 molecule of P4O12 has 4 atoms of P

Number of atoms of P

2.02E24*4/1=8.08 E24 P atoms

Number of O atom

2.02E24*12/1=2.42 E25 O atoms