Question

Ex. Calculate the boiling point elevation and the freezing point depression of a 250g of ethylene glycol that dissolves in 750g of water. Kb of the solvent is 0.510c/m and its Kf is 1.86oc/m linn. dolta Tbkbimi

Answer 1

1mol 250 g x 62.07 g 5.37 m Molality of the soluti on 0.750 kg Molal depression constant of water, k, = 1.86°Cm According to the depreassion in freezing point, A Depreassion in freezing point A k x m = k x m - ) 5.37 1.86 = 9.99°C Freezing point of soluti on, water sorent soh =0.00°C-9.99°C = -9.99° C 1 mol 250 g x 62.07 g 5.37 m Molality of the soluti on 0.750 kg Molal elevation constant of water, K = 0.512 Clm Elevation in boiling point, At, = k,x m 0.512 °C x5.37 m 2.75 °C Boiling point of solution toh At tter =2.75C +100° C 102.75°C