Question

A 125-g sample of Fe2O3 contains how many moles?

1.99 x 104 mol
0.783 mol
1.28 mol
0.6268

Answer 1

To find the number of moles we must first calculate the molar mass( M) of Fe2O3

Molar mass = mass / number of moles

M(Fe2O3) = (55.8 ×2) + (16×3)

= 111.6 + 48

= 159.6 g/mol

number of moles = mass / molar mass

= 125g/159.6g/mol

= 0.783mol

Hope this helps