Question:

45 g of ethylene glycol $(C_2H_6O_2)$ is mixed with 600 g of water. The freezing point of the solution is ($K_f$ for water is $1.86\, K\, kg\, mol^{-1}$)

Updated On: Jun 23, 2023
  • 273.95 K
  • 270.95 K
  • 370.95 K
  • 373.95 K
Hide Solution
collegedunia
Verified By Collegedunia

The Correct Option is B

Solution and Explanation

Depression in freezing point is related to the molality, therefore, the molality of the solution with respect to ethylene glycol $= \frac{moles \,of\, ethylene \,glycol}{mass \,of \,water \,in \,kilogram}$ Moles of ethylene glycol $= \frac{45 g }{62\, g \,mol^{-1}} = 0.73 \,mol$ Mass of water in $kg =\frac{600\, kg}{1000 \,kg} = 0.6\, kg$ Hence, molality of ethylene glycol $= \frac{0.73\, mol}{0.60\, kg} = 1.2\, mol\, kg^{-1}$ Therefore, freezing point depression, $?T_{f} = 1.86\, K\, kg\,mol^{-1} ? 1.2 \,mol \,kg^{-1} = 2.2\, K$ Freezing point of the aqueous solution $= 273.15\, K - 2.2\, K = 270.95 \,K$
Was this answer helpful?
0
0

Concepts Used:

Solutions

A solution is a homogeneous mixture of two or more components in which the particle size is smaller than 1 nm.

For example, salt and sugar is a good illustration of a solution. A solution can be categorized into several components.

Types of Solutions:

The solutions can be classified into three types:

  • Solid Solutions - In these solutions, the solvent is in a Solid-state.
  • Liquid Solutions- In these solutions, the solvent is in a Liquid state.
  • Gaseous Solutions - In these solutions, the solvent is in a Gaseous state.

On the basis of the amount of solute dissolved in a solvent, solutions are divided into the following types:

  1. Unsaturated Solution- A solution in which more solute can be dissolved without raising the temperature of the solution is known as an unsaturated solution.
  2. Saturated Solution- A solution in which no solute can be dissolved after reaching a certain amount of temperature is known as an unsaturated saturated solution.
  3. Supersaturated Solution- A solution that contains more solute than the maximum amount at a certain temperature is known as a supersaturated solution.