Question

A complex of iron contains 45.6% Fe by mass. Find out the no. of Fe atoms in 5.0g of this complex?

Answer 1

Given percentage by mass of Fe in the compound = 45.6%
That means 100g of the substance contains 45.6g of Fe, So 5g of the substance will contain x grams of Fe.
=> x = (45.6 x 5)/100 = 2.28g

Now no. of atoms = Moles x Avogadro No.
=> No. of atoms = (Given Mass of Fe/Molar Mass of Fe) x 6.02 x 10^23
= (2.28/56) x 6.02 x 10^23
= 2.450 x 10^22 atoms of Fe.

Answer 2

Answer:

Given percentage by mass of Fe in the compound = 45.6%

That means 100g of the substance contains 45.6g of Fe, So 5g of the substance will contain x grams of Fe.

=> x = (45.6 x 5)/100 = 2.28g

Now no. of atoms = Moles x Avogadro No.

=> No. of atoms = (Given Mass of Fe/Molar Mass of Fe) x 6.02 x 10^23

= (2.28/56) x 6.02 x 10^23

= 2.450 x 10^22 atoms of Fe.

Explanation: