Question

Which of the following solutes, dissolved in 1000 g of water, would provide a solution with the lowest freezing point? 0.045 mol of barium chloride, MgCl2 0.045 mol of ammonium nitrate, NH Br 0.045 mol of acetic acid, CH3COOH 0.045 mol of urea, CO(CH3)2 0.045 mol of calcium sulfate, BaSO4

Answer 1

Lowering of freezing point is colligative property, lies this property depends on the number of particles present maide the solution. The solution in which number of particles are greater there the lowering of freeting point also will be greater. in the 0.045 M) a MgCl solution, Migel a Moz+ +200-tie per moleante & there are 3 particles in the 0. 045 (M) Nha Br solution, NHA Br NHAT & Br ie. per molecule there are 2 particles. in 0.045 (M) A solution, 2 CH3 200H = 20 ---H-0. CH3-6 T he -et's ore here associetion Beebres so, per molecule there are V particles. ie. two molecule combine to foom I particle. in 0.045 M CO (NH2), per molecule only 1 pesticte. As no emociotion / dissociation occorres. in 0.045 M Basoa solution, there are a particles Basoa Baht + 50% per molecule. + So, lowering of the freezing point will be mont tor. 0.045 M MgCla solution or in this solution the number of particles in 3 per Mglla solution 30, 0.848 M Mg URL will have lowest freezing point N.B. As molarity of each solution are same so, sember of molecules are some for each solution.