Calculate the no. of atoms of each element persent in 9.8 g of sulphuric acid, H₂SO₄. (H=1, S=32, O=16)

Molecular weight of H₂SO₄ = 98

  9.8 gm of H₂SO₄ = 9.8/98 = 0.1mole

  1 mole = 6.023 x 10²³ molecules

0.1  Mole = 6.023 x 10²² molecules.

One molecule of H₂SO₄ = 2 hydrogen atom, one sulphur atom and 4 oxygen atoms therefore

Number of hydrogen atom in 0.1 mole = 2 x 6.023 x 10²²

  = 12.046 x 10²²

Number of sulphur atom in 0.1 mole = 1 x 6.023 x 10²²

  = 6.023 x 10²²

Number of oxygen atom in 0.1 mole = 4 x 6.023 x 10²²

  = 24.092 x 10²²