When BrO₃^- ion reacts with Br in acid medium, Br₂ is liberated. The equivalent mass of Br₂ in this reaction is :

2BrO₃^- + 12H⁺ + 10Br^- → 6Br₂ + 6H₂O
10 moles $\overline{\mathrm{e}}$ are required for formation of 6 moles of Br₂
no. of Br₂ = 10/6 = 5/3
eq. wt = mol.wt/n = m/5/3 = 3M/5