Calculate number of atoms in given moles of a substance | ClassNotes

Oct 16, 2022

Zn is a silvery metal that is used to galvanize steel to prevent corrosion. How many atoms are there in 1.25 mole of Zn?
A thin foil of aluminum (Al) is used as wrapper in food industries. How many atoms are present in a foil that contains 0.2 moles of aluminum?

Difficulty: Medium

Solution:

(a) 1 mole of Zn contains 6.022 x 10²³ atoms

1.25 moles of Zn contain = 6.022 x 10²³ x 1.25 = 7.53 x 10²³ Zn atoms

(b) 1 mole of Al contains 6.022 x 10²³

0.2 moles of Al will contain = 6.022 x 10²³ x 0.2 = 1.2044 x 10²³ atoms