List of top Chemistry Questions on Colligative Properties asked in JEE Main

$W$ g of a non-volatile electrolyte solid solute of molar mass $M\,\text{g mol}^{-1}$ when dissolved in $100\,\text{mL}$ water decreases vapour pressure of water from $640\,\text{mm Hg}$ to $600\,\text{mm Hg}$. If aqueous solution of the electrolyte boils at $375\,\text{K}$ and $K_b$ for water is $0.52\,\text{K kg mol}^{-1}$, then the mole fraction of the electrolyte $(x_2)$ in the solution can be expressed as ___.
(Given: density of water $=1\,\text{g mL}^{-1}$, boiling point of water $=373\,\text{K}$)

A solution is prepared by dissolving 0.3 g of a non-volatile non-electrolyte solute A of molar mass 60 g mol$^{-1}$ and 0.9 g of a non-volatile non-electrolyte solute B of molar mass 180 g mol$^{-1}$ in 100 mL H$_2$O at 27$^\circ$C. Osmotic pressure of the solution will be
[Given: R = 0.082 L atm K$^{-1}$ mol$^{-1}$]

1 g of AB₂ is dissolved in 50 g solvent such that $\Delta T_f = 0.689$. When 1 g AB is dissolved in 50 g of same solvent, $\Delta T_f = 1.176$. Find molar mass of AB₂. $K_f = 5 \, \text{kg/mol}$. AB₂ and AB are non-electrolytes. (Report to nearest integer)

If $A_2B \;\text{is} \;30\%$ ionised in an aqueous solution, then the value of van’t Hoff factor $ i $ is:

HA $ (aq) \rightleftharpoons H^+ (aq) + A^- (aq) $ The freezing point depression of a 0.1 m aqueous solution of a monobasic weak acid HA is 0.20 °C. The dissociation constant for the acid is Given: $ K_f(H_2O) = 1.8 \, \text{K kg mol}^{-1} $, molality ≡ molarity

The percentage dissociation of a salt (MX$_3$) solution at a given temperature (van't Hoff factor $i = 2$) is .................. % (Nearest integer)

Given below are two statements:
Statement (I): Molal depression constant $ k_f $ is given by $ \frac{M_1 R T_f}{\Delta S_{\text{fus}}} $, where symbols have their usual meaning.
Statement (II): $ k_f $ for benzene is less than the $ k_f $ for water.
In light of the above statements, choose the most appropriate answer from the options given below:

Given below are two statements:
Statement (I): NaCl is added to the ice at $ 0^\circ C $, present in the ice cream box to prevent the melting of ice cream.
Statement (II): On addition of NaCl to ice at $ 0^\circ C $, there is a depression in freezing point.
In the light of the above statements, choose the correct answer from the options given below:

1.24 g of $AX_2$ (molar mass 124 g mol$^{-1}$) is dissolved in 1 kg of water to form a solution with boiling point of 100.105°C, while 2.54 g of AY_2 (molar mass 250 g mol$^{-1}$) in 2 kg of water constitutes a solution with a boiling point of 100.026°C. $Kb(H)_2$$\text(O)$ = 0.52 K kg mol$^{-1}$. Which of the following is correct?

CrCl$_3$.xNH$_3$ can exist as a complex. 0.1 molal aqueous solution of this complex shows a depression in freezing point of 0.558°C. Assuming 100\% ionization of this complex and coordination number of Cr is 6, the complex will be:

Arrange the following solutions in order of their increasing boiling points.
(i) $10^{-4}$ M NaCl
(ii) $10^{-4}$ M Urea
(iii) $10^{-3}$ M NaCl
(iv) $10^{-2}$ M NaCl

Consider the given plots of vapor pressure (VP) vs temperature (T/K). Which amongst the following options is the correct graphical representation showing $ \Delta T_f $ depression in the freezing point of solvent in a solution?

A solution containing $10 \, \text{g}$ of an electrolyte $AB_2$ in $100 \, \text{g}$ of water boils at $100.52^\circ \text{C}$. The degree of ionization of the electrolyte ($\alpha$) is _____ $\times 10^{-1}$. (nearest integer)
$[ \text{Given: Molar mass of } AB_2 = 200 \, \text{g mol}^{-1}, \, K_b \, (\text{molal boiling point elevation const. of water}) = 0.52 \, \text{K kg mol}^{-1}, \text{ boiling point of water} = 100^\circ \text{C}; \, AB_2 \text{ ionises as } AB_2 \rightarrow A^{2+} + 2B^- ]$

Consider the dissociation of the weak acid HX as given below:
\[\text{HX(aq)} \rightleftharpoons \text{H}^+(\text{aq}) + \text{X}^-(\text{aq}), \, K_a = 1.2 \times 10^{-5}\]
$[K_a: \text{dissociation constant}]$
The osmotic pressure of $0.03 \, \text{M}$ aqueous solution of HX at 300 K is ______ $ \times 10^{-2} \, \text{bar} $ (nearest integer).
Given: $R = 0.083 \, \text{L bar mol}^{-1} \text{K}^{-1}$

Considering acetic acid dissociates in water, its dissociation constant is $6.25 \times 10^{-5}$. If 5 mL of acetic acid is dissolved in 1 litre water, the solution will freeze at $-x \times 10^{-1}$ °C, provided pure water freezes at 0 °C. $x = $ _____ (Nearest integer)
Given: $(K_f)_{water} = 1.86$ K kg mol$^{-1}$
density of acetic acid is 1.2 g mol$^{-1}$
molar mass of water = 18 g mol$^{-1}$
molar mass of acetic acid = 60 g mol$^{-1}$
density of water = 1 g cm$^{-3}$
Acetic acid dissociates as CH$_3$COOH $\rightleftharpoons$ CH$_3$COO$^-$ + H$^+$

0.05M CuSO$_4$ when treated with 0.01M K$_2$Cr$_2$O$_7$ gives green colour solution of Cu$_2$Cr$_2$O$_7$. The \[ \text{[SPM : Semi Permeable Membrane]} \]

$K_2Cr_2O_7$		$CuSO_4$
Side X	SPM	Side Y

Due to osmosis:

An artificial cell is made by encapsulating $0.2 \, \text{M}$ glucose solution within a semipermeable membrane. The osmotic pressure developed when the artificial cell is placed within a $0.05 \, \text{M}$ solution of NaCl at 300 K is ______ $ \times 10^{-1} \, \text{bar} $. (Nearest Integer)
Given: $R = 0.083 \, \text{L bar mol}^{-1} \text{K}^{-1}$
Assume complete dissociation of NaCl.

We have three aqueous solutions of NaCl labelled as ‘A’, ‘B’ and ‘C’ with concentration 0.1 M, 0.01M & 0.001 M, respectively. The value of vant’ Haft factor (i) for these solutions will be in the order.

What happens to freezing point of benzene when small quantity of napthalene is added to benzene?

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 :

$25 \,mL$ of an aqueous solution of $KCl$ was found to require $20\, mL$ of $1\, M$ $AgNO _3$ solution when titrated using $K _2 CrO _4$ as an indicator What is the depression in freezing point of $KCl$ solution of the given concentration? _________ (Nearest integer) (Given: $K _f=20 \,K \,kg \,mol ^{-1}$)
Assume 1) $100 \%$ ionization and
2) density of the aqueous solution as $1 \,g \,mL ^{-1}$

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 :

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

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 $K _f=1.8\, K \,kg\, mol ^{-1}$