How many atoms of S are in the following formula: 3Na(SO4)2

1) 6
2) 8
3) 3
4) 5

Calculate the molar mass of aluminum oxide (al2o3). express your answer to four significant figures.

In the millikan oil drop experiment they determined that every drop had a charge which was a while number multiple of -1.60x10^-19. if a drop has a total charge of -9.60x10^-19 then how many excess electrons are contained within the drop?

The molality of calcium chloride (cacl2) in an aqueous solution is 2.46 m. what is mole fraction of the solute?