SolutionHard
Question
64.4g Crystals of pure Na2SO4 10 H2O are dissolved in 114 g of water to obtain an aq. solution of salt. Determine the freezing point of solution assuming that salt is completely ionized in solution Kf of water is 1.86 K kgmol-1 :-
Options
A.-7.44oC
B.-9.79oC
C.-3.26oC
D.-2.48oC
Solution
Moles of solute (n) = 
= 0.2 mol Na2SO4 10 H2O
∵ 1 mol Na2SO4 10H2O contains = 10 mol H2O
⇒ 180 gH2O
∴ 0.2 mol Na2SO4 10H2O contains = 180 × 0.2 = 36 g H2O
Total mass of solvent (H2O) in solu. = 114 + 36 = 150 g
∴ ᐃTf = 3 × 1.86 ×
= 7.44
= 0.2 mol Na2SO4 10 H2O∵ 1 mol Na2SO4 10H2O contains = 10 mol H2O
⇒ 180 gH2O
∴ 0.2 mol Na2SO4 10H2O contains = 180 × 0.2 = 36 g H2O
Total mass of solvent (H2O) in solu. = 114 + 36 = 150 g
∴ ᐃTf = 3 × 1.86 ×
= 7.44Create a free account to view solution
View Solution FreeMore Solution Questions
Kf for water is 1.86 K kg mol-1. If your automobile radiator holds 1.0 kg of water, how many grams of ethylene glycol (C...Phenol dimerizes in benzene. If the observed molecular mass of phenol in solution is 120, then its degree of dimerizatio...For a solution of 0.849 g of mercurous chloride in 50 g of HgCl2(l) the freezing point depression is 1.24oC. Kf for HgCl...We have 100 mL of 0.1 M KCl solution. To make it 0.2 M,...Three solutions of HCl having normality 12 N, 6 N and 2 N are mixed to obtain a solution of 4 N normality. Which among t...