In Carius method, chlorine is converted to AgCl.
Molar mass of AgCl = 143.5 g/mol.
Moles of AgCl formed = 0.5253 / 143.5 = 0.003661 mol.
Since each AgCl contains one Cl atom, moles of Cl = 0.003661 mol.
Mass of Cl = 0.003661 × 35.5 = 0.1300 g.
Percentage of Cl = (0.1300 / 0.2425) × 100 = 53.58%.