Question

Which of the following has the largest number of Oxygen atoms-

(a)1 gram of Oxygen atoms

(b)1 gram of Oxygen molecule

(c)1 gram of Ozone

SOLVE FOR (a),(b) and (c)

Answer 1

a) 1 mole of oxygen atom = 16 g = 6.022 $\times$10²³ atoms
that is, 16 g of oxygen atom contains 6.022 $\times$ 10²³ atoms
Thus, 1 g of oxygen contain = $\frac{6.022\times {10}^{23}}{16}$ atoms
= 0.376 $\times$ 10²³ atoms

b) 1 mole of oxygen molecule = 32 g = ​6.022 $\times$10²³ molecules
that is, 32 g of oxygen molecule contains 6.022$\times$ 10²³ molecules
Thus, 1 g of oxygen molecule contain = $\frac{6.022\times {10}^{23}}{32}$ molecules
= 0.1882 $\times$ 10²³ molecules
Now, since 1 molecule of oxygen contain 2 atoms of oxygen.
Therefore, ​0.1882 $\times$ 10²³ molecules will contain 2 $\times$ ​0.1882 $\times$ 10²³ atoms
= 0.376 $\times$ 10²³ atoms

c) 1 mole of ozone = 48 g = ​6.022 $\times$10²³ molecules
that is, 48 g of ozone contains 6.022$\times$ 10²³ molecules
Thus, 1 g of ozone contain = $\frac{6.022\times {10}^{23}}{48}$ molecules
= 0.125 $\times$ 10²³ molecules
Now, since 1 molecule of ozone contain 3 atoms of oxygen.
Therefore, ​0.125 $\times$ 10²³ molecules will contain 3 $\times$ ​0.125 $\times$ 10²³ atoms
= 0.376 $\times$ 10²³ atoms

Thus, 1 g of oxygen , 1 g of oxygen molecule and 1 g of ozone will contain same number of oxygen atoms.