Final answer:
To prepare 100 ml of 0.1 M NaOH, calculate the mass by multiplying the molarity (0.1 M), volume (0.1 L), and molar mass of NaOH (40 g/mol). The result is 0.4 grams needed.
Step-by-step explanation:
To calculate the mass of sodium hydroxide (NaOH) needed to prepare 100 ml of 0.1 M solution, you can use the formula Mass = Molarity × Volume × Molar Mass. First, you need to convert the volume from milliliters to liters. Since there are 1000 milliliters in a liter, 100 ml is equivalent to 0.1 liters. Next, look up the molar mass of NaOH, which is approximately 40 g/mol. Now you can use the formula:
Mass = 0.1 M × 0.1 L × 40 g/mol
Mass = 0.01 × 40 = 0.4 g
So, you need 0.4 grams of NaOH to prepare the desired solution. This calculation is a typical task in stoichiometry, which is a branch of chemistry that involves determining the quantities of reactants and products in chemical reactions.