9. The molar mass of Na2SO4 is 142.1 g/mol.
Calculate the number of moles in 10.0 g of Na2SO4.

• 7 x 6.02 x 10^23 x 142.1 g/mol
• 10.0 g/ 142.1 g/mol
• 7 x 10.0g/142.1 g/mol
• 10.0g x 142.1 g/mol