Question

How many molecules are present in 710 g of chlorine gas (cl 2)? What will be the total number of atoms in it?

Answer 1

Dear student,

The molar mass of chlorine is 35.5 g. So the molar mass of Cl₂ gas is 2 X 35.5 = 71 g. Now we know that there are 6.023 X 10²³ particles in one mole of substance. Hence

71 g of Cl₂ = 6.023 X 10²³ molecules of Cl₂ gas

1 g of Cl₂ = (6.023 X 10²³) / 71 molecules of Cl2 gas

So 710 g of Cl2 = (6.023 X 10²³X 710) / 71 molecules of Cl₂ gas

= 6.023 X 10²⁴ molecules of Cl₂ gas

A mole of Cl₂ gas contains 6.022×10²⁴ molecules, but each molecule of chlorine gas contains two atoms.

Total number of atoms present in Cl₂ = (6.023 x 10²⁴ x 2) = 12.046 x 10 ²⁴ atoms

Regards,