Final answer:
To prepare 1 Liter of 0.2% sodium hypochlorite from a 5% solution, you need to dilute 40 mL of the 5% solution up to 1 Liter with water.
Step-by-step explanation:
The student asked how to prepare 1 Liter (1000 ml) of 0.2% sodium hypochlorite solution from a bottle that contains 5% chlorine, which is typically sodium hypochlorite.
To prepare this solution, you would use the dilution formula: C1V1 = C2V2, where C1 and V1 are the concentration and volume of the starting solution, and C2 and V2 are the concentration and volume of the final solution. In this case, C1 is 5%, C2 is 0.2%, and V2 is 1,000 mL (1 Liter). Rearranging the formula to solve for V1 (the volume of the starting solution you need) gives V1 = C2V2 / C1.
Plugging in the known values: V1 = (0.2%*1000 mL) / 5% = 40 mL. This means you need to take 40 mL of the 5% bleach solution and dilute it with water until the total volume of the mixture is 1 Liter. When measuring out the 40 mL of concentrated bleach, it's essential to use a pipette or a measuring cylinder for accuracy. After adding the 5% solution to a volumetric flask, add distilled water up to the 1 Liter mark to achieve the desired concentration.