Question

the no of atoms in 20 g of so3 is approximately

Answer 1

As we know 1 mole of any substance contains 6.023×10^23 atoms.
And we know that mass of 1 mole of any substance is just it's molecular mass expressed in grams.
1 mole of so3 weighs 80gm.
the given mass =20gm
as we know
(given mass)/molar mass =no. of moles
20gm/80gm= 1/4
no. of atoms in 1 mole= 6.023×10^23
no. of atoms in 1/4 mole= 1.50575×10^23