Question

A sample of iron has a mass of 5.6g calculate (a)the number of moles of iron present (b)the number of atoms of iron in the sample​

Answer 1

Mass of iron present in the sample = 5.6g

mass of 1 mole of iron = 56g

a) No. of moles of iron in the sample = given mass/molar mass = 5.6/56 = 0.1 mol

1 mol of iron has 6.02 x 10^23 atoms

b) 0.1 mole has 6.02 x 0.1 x 10^23 = 6.02 x 10^22 atoms