Find the number of oxygen atoms in 5 moles of H2SO4.
1 molecule of sulphuric acid has 4 atoms of oxygen
1 mole of sulphuric acid will have 4 moles of oxygen.
5 mole of sulphuric acid will have 20 moles of oxygen.
So the total number of atoms are 4×5×6.023×1023
120.46×1023 atoms of oxygen.