Question

How many oxygen atoms are in 10.0 g of Fe2O3.

Answer 1

Given 10g of fe2O3 Wen know - No. of moles (n) = - - Weight taken of Substance (W) Molecular weight of substance (M) Given - . W of Fe₂O3 = 10q M of Fe, O3 = 159.7 g/mol. (known) w 1000 g no, moles. Of PeqO3 = M 159.7 g/mol = 0.0626 mol, :

Also we know- have In a mole of any Substance, 6.023 x 1023 molecules present. :. No. of molecules present in 0.0626 mole of fe₂O3 in = 0.0626 X 6.023 x 1023 .. = 3.77 X1022

Oxygen aram Now, Dn one fez O molecule there are three present. i No. of oxygen atom present in 3.77x1022 of fez O3 is = 3 x (3.77 x1022) = 4.131 x 1023 molecules is No. of oxygen alom present in 10.0 g Fe₂O3 in 1.131 x 1020 Am.