To prepare 200 ml of a 20% NaOH (sodium hydroxide) solution, you'll need to follow these steps:
Determine the amount of NaOH needed: The percentage of a solution refers to the weight/volume ratio. In this case, a 20% NaOH solution means 20 grams of NaOH per 100 ml of solution. Since you want to prepare 200 ml of solution, you'll need (20 grams/100 ml) x 200 ml = 40 grams of NaOH.
Weigh the required amount of NaOH: Use a balance or scale to accurately measure out 40 grams of NaOH. Make sure to handle NaOH with caution as it is a caustic substance. Wear appropriate protective equipment, such as gloves and goggles.
Dissolve NaOH in water: Add the 40 grams of NaOH to a suitable container, such as a beaker. Then, slowly add distilled or deionized water to the container while stirring continuously until the NaOH is completely dissolved.
Adjust the final volume: After the NaOH is dissolved, continue adding water while stirring until the total volume reaches 200 ml. Ensure thorough mixing to achieve a homogeneous solution.
Safety precautions: Remember to exercise caution when handling NaOH, as it is a strong base that can cause burns. Be sure to work in a well-ventilated area, wear appropriate safety equipment, and handle the chemicals responsibly.
It's important to note that handling chemicals and preparing solutions requires knowledge of proper laboratory techniques and safety procedures. If you are not experienced in working with chemicals, it is advisable to seek guidance from a trained professional or refer to established laboratory protocols.