Question

Calculate the mass of O₂ molecule?

Answer 1

Molecular mass:

1. The molecular mass of an element is defined as the sum of the masses of all the atoms present in the molecule.
2. Molecular mass is obtained by adding the atomic masses of all atoms with the number of atoms in the molecule.

Calculating the mass of oxygen molecule

Mass of one oxygen atom $=16\mathrm{g}$

Mass of 1 mole of O₂ molecule $=2\times 16=32\mathrm{g}$

Number of molecules in 1 mole $=6.022\times {10}^{23}$

Mass of 1 molecule of O₂ is $=\frac{32}{6.022\times {10}^{23}}=5.32\times {10}^{-23}\mathrm{g}$

Hence, the mass of 1 molecule of O₂ is $5.32\times {10}^{-23}\mathrm{g}$