What would be the van't Hoff factor for a solution prepared by dissolving 3.42 ~g of CaCl ₂ in 2500 ~ml of water having an Osmotic pressure equal to 0.75 ~atm . at 27^ C ? Molar mass of CaCl ₂=111 ~amu .

Step-by-step solution

The osmotic pressure formula is given by = iCRT , where i is the van't Hoff factor, C is the molar concentration, R is the gas constant, and T is the temperature in Kelvin. Given values: Mass of CaCl ₂ = 3.42 g Molar mass of CaCl ₂ = 111 g/mol Volume of solution V = 2500 ml = 2.5 L Osmotic pressure = 0.75 atm Temperature T = 27^ C = 300 K Gas constant R = 0.0821 L atm K ⁻¹ mol ⁻¹ Calculate the number of moles of CaCl ₂ : n = 3.42 111 0.03081 mol Calculate the molar concentration C : C = n V = 0.03081 2.5 = 0.012324