To prepare a 250 mL .25 molal solution of CaCl2, one must first calculate the number of moles required using the formula for molality, which is defined as moles of solute per kilogram of solvent. Given that CaCl2 has a molar mass of 110.98 g/mol, for a .25 molal solution, 0.025 moles of CaCl2 are needed. This translates to approximately 2.77 grams of CaCl2, which should be dissolved in water, ensuring the total mass of the solvent is 250 mL, accounting for the density of water.
PREREQUISITESChemistry students, laboratory technicians, and educators involved in solution preparation and chemical calculations.