Question

Calculate no. Of C, O and H atoms in 72.5g C3H7OH ( molar mass = 60 ).

Answer 1

C3H7OH - Molecular mass = 60

72.5 g is 72.5/60 = 1.208 moles

1 mole of C3H7OH contains 3N atoms ( N= 6.023 x 10^23) of C

1.208 moles contains 1.208 x 3N atoms = = 3.624N atoms of C

= 2.183 x 10^24 atoms of C

Similarly

no. of H atoms = 1.208 x 8N = 9.664N atoms

= 5.82 x 10^24 atoms of H

no.of O atoms = 1.208N atoms = 7.276 x 10^23 atoms of O