Question

the total no. of oxygen atoms present in one molecule of sodium sulphate is

Answer 1

The formula of sodium sulphate is Na₂SO₄​.
There are 4 O atoms in the formula.

Now one molecule contains = 6.023 $\times$ 10²³ atoms
Thus, one molecule of Na₂SO₄ contains = $4\times 6.023\times {10}^{23}$ atoms of oxygen
= 24.092$\times$10²³ atoms of oxygen