Aluminum oxide, Al2O3, is used as a filler for paints and varnishes as well as in the manufacture of electrical insulators. Calculate the number of moles in 47.51 g of Al2O3.

the number of moles in 47.51 g of Al2O3.

let M is the molar mass

and n the number of moles

we know that M = m / n where m is the mass

so we can get n = m/M

M (Al2O3) = 2*27+3*16=102

n=74.51/102 = 0.46 mole

the answer is

0.46 mole