How many moles are in 458 grams of na2so4

# moles = mass (g) / Mr (relative atomic mass)

# moles = 458 / ((23*2)+32+(16*4)

# moles= 458 /  142 = 3.2253521126760...

= 3.23 moles

what is the volume occupied by 40 grams of argon gas (ar) at standard conditions? what volume, in liters, is occupied by 1.5 x 1023 

by cartels in other countries, shipped by air, mail, or land. i cant really see your answer choices : /