List of top Chemistry Questions on Colligative Properties

A sample of water is found to contain 5.85% \((\frac{w}{w})\) of AB (molecular mass 58.5) and 9.50% \((\frac{w}{w})\) XY₂ (molecular mass 95). Assuming 80% ionisation of AB and 60% ionisation of XY₂ , the freezing point of water sample is
[Given : K_f for water 1.86 K kg mol^-1 , Freezing point of pure water is 273 K and A, B and Y are monovalent ions]

Two solutions $A$ and $B$ are prepared by dissolving $1 g$ of non-volatile solutes $X$ and $Y$ respectively in $1 \,kg$ of water The ratio of depression in freezing points for $A$ and $B$ is found to be $1: 4$ The ratio of molar masses of $X$ and $Y$ is :

Evaluate the following statements for their correctness
A. The elevation in boiling point temperature of water will be same for $01 \,M \,NaCl$ and $01\, M$ urea
B. Azeotropic mixtures boil without change in their composition
C. Osmosis always takes place from hypertonic to hypotonic solution
D. The density of $32 \% H _2 SO _4$ solution having molarity $409\, M$ is approximately $126\, g mL ^{-1}$
E. A negatively charged sol is obtained when KI solution is added to silver nitrate solution
Choose the correct answer from the options given below :

Freezing point of solution is less than that of pure solvent, which of the following statements are correct ? 
(A) Vapour pressure of solution is less than that of pure solvent 
(B) Vapour pressure of solution is greater than that of pure solvent 
(C) Only solvent molecules will freeze 
(D) Only solute molecules will freeze

Match List I and List II

List II	List II
A. van't Hoff factor, i	I. Cryoscopic constant
B. $k_f$	II. Isotonic solutions
C. Solution with same  with same osmotic pressure	III.  Normal molar mass /Abnormal molar mass
D. Azeotropes	IV. Solutions with same composition of  vapour above it

Choose the correct answer from the options given below :

At $27^{\circ} C$, a solution containing $25 \,g$ of solute in $2500 \,mL$ of solution exerts an osmotic pressure of $400 \,Pa$. The molar mass of the solute is ____ $g\,mol ^{-1}$. (Nearest integer)
(Given : $R =0.083 \,L\,bar\, K ^{-1} \,mol ^{-1}$ )

Lead storage battery contains $38 \%$ by weight solution of $H _2 SO _4$ The van't Hoff factor is $2.67$ at this concentration The temperature in Kelvin at which the solution in the battery will freeze is ______(Nearest integer) Given $K _f=1.8\, K \,kg\, mol ^{-1}$

A solution containing 2.5 × 10^–3 kg of a solute dissolved in 75 × 10^–3 kg of water boils at 373.535 K. The molar mass of the solute is _____ g mol^–1. [nearest integer] (Given : K_b(H₂O) = 0.52 K kg mol^–1 and boiling point of water = 373.15 K)

The following solutions were prepared by dissolving $10 g$ of glucose $\left( C _{6} H _{12} O _{6}\right)$ in $250 \,ml$ of water $\left( P _{1}\right)$ $10 \,g$ of urea $\left( CH _{4} N _{2} O \right)$ in $250 \,ml$ of water $\left( P _{2}\right)$ and $10 g$ of sucrose $\left( C _{12} H _{22} O _{11}\right)$ in $250\, ml$ of water $\left( P _{3}\right)$. The right option for the decreasing order of osmotic pressure of these solutions is:

If 8 g of a non-electrolyte solute is dissolved in 114 g of n-octane to reduce its vapour pressure to 80%, the molar mass (in g mol^-1) of the solute is
[Given that the molar mass of n-octane is 114 g mol^-1.]

A sol of $AgI$ is prepared by mixing equal volumes of $0.1M \, AgNO_3$ and $0.2M KI$, which of the following statement is correct ?

Which of the following pair of solutions is isotonic ?

Which of the following colligative properties can provide molar mass of proteins (or polymers or colloids) with greatest precision?

Molal depression constant for a solvent is $4.0\, kg\, mol^{-1}$. The depression in the freezing point of the solvent for $0.03\, mol\, kg^{-1}$ solution of $ {K2SO4}$ is : (Assume complete dissociation of the electrolyte)

The elevation in boiling point of $0.25$ molal aqueous solution of a substance is $(K_b = 0.52\, K\, kg\, mol^{-1})$

Which of the following colligative properties can provide molar mass of proteins (or polymers or colloids) with greatest precision?

Chloroform, $CHCl _{3}$, boils at $61.7^{\circ} C$. If the $K_{b}$ for chloroform is $3.63^{\circ} C / molal$, what is the boiling point of a solution of $15.0\, kg$ of $CHCl _{3}$ and $0.616\, kg$ of acenaphthalene, $C _{12} H _{10}$ ?

Which have Vont Hoff factor same as K₄[Fe(CN)₆] ?

pH of a $0.1\, M$ monobasic acid is found to be $2$. Hence, its osmotic pressure at a given temperature $TK$ is

Osmotic pressure of 0.4% urea solution is 1.64 atm and that of 3.42% cane sugar is 2.46 atm. When the above two solutions are mixed, the osmotic pressure of the resulting solution is:

The Tyndall effect is observed only when following conditions are satisfied (a) The diameter of the dispersed particles is much smaller than the wavelength of the light used. (b) The diameter of the dispersed particle is not much smaller than the wavelength of the light used (c) The refractive indices of the dispersed phase and dispersion medium are almost similar in magnitude (d) The refractive indices of the dispersed phase and dispersion medium differ greatly in magnitude

Raoult?s law becomes a special case of Henry?s law when

Pure water freezes at $273 \,K$ and $1$ bar. The addition of $34.5\, g$ of ethanol to $500\, g$ of water changes the freezing point of the solution. Use the freezing point depression constant of water as $2\,K\, kg\,mol^{-1}$. The figures shown below represent plots of vapour pressure (V.P.) versus temperature (T). [molecular weight of ethanol is $46\, g\,mol^{-1}$] Among the following, the option representing change in the freezing point is

Two elements $A$ and $B$ form compounds of formula $AB_2$ and $AB_4$. When dissolved in $20.0\, g$ of benzene $1.0 \,g$ of $AB_2$ lowers f. pt. by 2.3$^{\circ}$C whereas $1.0\, g$ of $AB_4$ lowers f. pt. by 1.3$^{\circ}$C. The $K_f$ for benzene is $5.1$. The atomic masses of $A$ and $B$ are