Home
Class 12
CHEMISTRY
Equimolal solutions KCl and compound X i...

Equimolal solutions `KCl` and compound `X` in water show depression in freezing point in the ratio of `4:1`, Assuming `KCl` to be completely ionized, the compound `X` in solution must

A

Dissociate to the extent of `50%`

B

Hydrolyze to the extent of `80%`

C

Dimerize to the extent of `50%`

D

Trimerize to the extent of `75%`

Text Solution

Verified by Experts

The correct Answer is:
D
`underset(("p moles"))(KCl) and underset(("p moles"))(X)`
`DeltaT_(f) (KCl)=iK_(f)m=2K_f m`
`DeltaT_f (X) = iK _f .m=1/2(2K_f m)rArr i=1/2 (lt1)`
`2X hArr X_2`
`{:(1,0),(1-alpha , a//2):}`
`i=1+alpha+alpha/3=1-(2alpha)/3=1/2rArr alpha=3/4=75%`
Promotional Banner

Similar Questions

Explore conceptually related problems

Equimolal solutions A and B show depression in freezing point in the ratio 2:1 . A remains in the normal state in solution. B will be

Depression in freezing point is __________pronounced if camphor is used as a solvent in place of water for same amount of solute and solvent.

0.01 M solution each of urea, common salt and Na_(2)SO_(4) are taken, the ratio of depression of freezing point is :

MX_(2) dissociates into M^(2+) and X^(ө) ion in an aqueous solution, with a degree of dissociation (alpha) of 0.5 . The ratio of the observed depression of freezing point of the aqueous solution to the value of the depression of freezing point in absence of ionic dissociation is

A system of greater disorder of molecules is more probable. The disorder of molecules is reflected by the entropy of the system. A liquid vapourizes to form a more disordered gas. When a solute is present, there is additional contribution to the entropy of the liquid due to increased randomness. As the entropy of solution is higher than that of pure liquid, there is weaker tendency to form the gas. Thus, a solute (non-volatile) lowers the vapour pressure of a liquid, and hence a higher boiling point of the solution. Similarly, the greater randomness of the solution opposes the tendercy to freeze. In consequence, a lower temperature must be reached for achieving the equilibrium between the solid (frozen solvent) and the solution. The elevation in boiling point (DeltaT_(b)) and depression in freezing point (DeltaT_(f)) of a solution are the colligative properties which depend only on the concentration of particles of the solute and not their identity. For dilute solutions, (DeltaT_(b)) and (DeltaT_(f)) are proportional to the molarity of the solute in the solution. A liquid possessing which of the following characteristics will be most suitable for determining the molecular mass of a compound by cryoscopic measurements?

A system of greater disorder of molecules is more probable. The disorder of molecules is reflected by the entropy of the system. A liquid vapourizes to form a more disordered gas. When a solute is present, there is additional contribution to the entropy of the liquid due to increased randomness. As the entropy of solution is higher than that of pure liquid, there is weaker tendency to form the gas. Thus, a solute (non-volatile) lowers the vapour pressure of a liquid, and hence a higher boiling point of the solution. Similarly, the greater randomness of the solution opposes the tendercy to freeze. In consequence, a lower temperature must be reached for achieving the equilibrium between the solid (frozen solvent) and the solution. The elevation in boiling point (DeltaT_(b)) and depression in freezing point (DeltaT_(f)) of a solution are the colligative properties which depend only on the concentration of particles of the solute and not their identity. For dilute solutions, (DeltaT_(b)) and (DeltaT_(f)) are proportional to the molarity of the solute in the solution. To aqueous solution of Nal , increasing amounts of solid Hgl_(2) is added. The vapour pressure of the solution

A system of greater disorder of molecules is more probable. The disorder of molecules is reflected by the entropy of the system. A liquid vapourizes to form a more disordered gas. When a solute is present, there is additional contribution to the entropy of the liquid due to increased randomness. As the entropy of solution is higher than that of pure liquid, there is weaker tendency to form the gas. Thus, a solute (non-volatile) lowers the vapour pressure of a liquid, and hence a higher boiling point of the solution. Similarly, the greater randomness of the solution opposes the tendercy to freeze. In consequence, a lower temperature must be reached for achieving the equilibrium between the solid (frozen solvent) and the solution. The elevation in boiling point (DeltaT_(b)) and depression in freezing point (DeltaT_(f)) of a solution are the colligative properties which depend only on the concentration of particles of the solute and not their identity. For dilute solutions, (DeltaT_(b)) and (DeltaT_(f)) are proportional to the molarity of the solute in the solution. A mixture of two immiscible liquids at a constant pressure of 1.0 atm boils at temperature