What is the amount of CaCl 2 in grams (i = 2.47) dissolved in 2.5 L of water such that its osmotic pressure is 0.75 atm at 27 o C.? Report your answer up to one decimal place.

Step-by-step solution

According to van't Hoff equation Osmotic pressure π = i CRT = in B RT V i = 2.47; V = 2.5 L; R = 0.0821 L atm K -1 mol -1 T = 27 + 273 = 300 K; π = 0.75 atm n B = π V iRT = 0.75 atm × 2.5 L 2.47 × 0.0821 L atm K - 1 mol - 1 × 300 K = 0.0308 mol Amount of CaCl 2 dissolved = n B × M B = (0.0308 mol) × (111 g mol -1 ) = 3.42 g