To prepare 0.5 N NaOH in 2.5 liters of water, you'll need to calculate the amount of NaOH required based on its molar mass and the desired normality. Here are the steps to follow:
Determine the molar mass of NaOH: Sodium (Na) has a molar mass of approximately 23 g/mol, Oxygen (O) has a molar mass of approximately 16 g/mol, and Hydrogen (H) has a molar mass of approximately 1 g/mol. So the molar mass of NaOH is approximately 23 + 16 + 1 = 40 g/mol.
Calculate the amount of NaOH required: To prepare a 0.5 N solution, you need 0.5 moles of NaOH per liter of solution. Since you want to prepare 2.5 liters of solution, you'll need 0.5 * 2.5 = 1.25 moles of NaOH.
Convert moles to grams: To convert moles to grams, you can use the molar mass of NaOH. Multiply the number of moles by the molar mass:
grams of NaOH = moles of NaOH * molar mass of NaOH = 1.25 moles * 40 g/mol = 50 grams
Dissolve 50 grams of NaOH in water: Weigh out 50 grams of NaOH and add it to a container. Then, gradually add water while stirring until the total volume reaches 2.5 liters.
Remember to handle NaOH with care as it is a strong base and can cause burns. Wear appropriate protective gear, such as gloves and goggles, and work in a well-ventilated area.