Home
Class 12
CHEMISTRY
x g of urea was dissolved in 500 g of wa...

`x g` of urea was dissolved in `500 g` of water and cooled upto `-0.5^(@)C` whereby `128 g` of ice separates out from the solution. If cryoscopic constant for water be `1.86^(@)C//m`. Calculate the value of `x`.

Text Solution

Verified by Experts

The correct Answer is:
6
Given, `Delta T_(f) = 0.5, K'_(f) = 1.86, m_(urea) = 60`
Depression will be caused by water which exist as liquid at `-0.5^(@)C`
`:. W = 500-128 = 372g`
Now, `Delta T_(f) = K'_(f) xx "molality" = (1000 xx K'_(f) xx w)/(mW)`
`:. 0.5 = (1000 xx 1.86 xx w)/(372 xx 60) rArr w = 6 g`
Promotional Banner

Topper's Solved these Questions

  • DILUTE SOLUTION AND COLLIGATIVE PROPERTIES

    P BAHADUR|Exercise Exercise 3B Objectice Problems|1 Videos

  • DILUTE SOLUTION AND COLLIGATIVE PROPERTIES

    P BAHADUR|Exercise Exercise 9 Advanced Numerical|12 Videos

  • CHEMICAL KINETICS

    P BAHADUR|Exercise Exercise 9|13 Videos

  • ELECTROCHEMISTRY

    P BAHADUR|Exercise Exercise (9) ADVANCED NUMERICAL PROBLEMS|36 Videos

Similar Questions

Explore conceptually related problems

4 g of a solute are dissolved in 40 g of water to form a saturated solution at 25^(@)C . Calculate the solubility of the solute.

5 g of a substance when dissolved in 50 g water lowers the freeezing by 1.2^(@)C . Calculate molecular wt. of the substance if molal depression constant of water is 1.86^(@)C K kg mole^(-1) .

6 g of a substance is dissolved in 100 g of water depresses the freezing point by 0.93^(@)C . The molecular mass of the substance will be: ( K_(f) for water = 1.86^(@)C /molal)

When a solution w g of urea in 1 Kg of water is cooled to -0.372^(@)C,200g of ice is separated .If K_(f) for water is 1.86K Kgmol^(-1) ,w is

60g of urea is dissolved in 1100g solution. To keep DeltaT//K_(f)" as "1" mol"//kg , water separated in the form of ice is

0.5 g KCl was dissolved in 100 g water, and the solution, originally at 20^(@)C froze at -0.24^(@)C . Calculate the percentage ionization of salt. K_(f) per 1000 g of water = 1.86^(@)C .

0.9 g urea when dissolved in 45 g water caused elevation of 0.17^(@)C in b.p. Calculate molecular elevation constant of water.

Dissolving 120g of urea (mol wt 60) in 100 g of water gave solution of density 1.158g//mL . The molarity of the solution is