Answer

Chlorine water is approx. 0.6% w/v i.e. 0.6g of chlorine dissolved in 100ml of water. Chlorine exists as Cl2. The relative atomic mass of Cl is 35.5, so Cl2 is 71 (approx.). Divide 0.6 by 71 = 0.00845 mol in 100ml. Multiply by 10 to give mol per litre = 0.085M or approx. 0.1M