Solutions

31 g of ethylene glycol is mixed with 500 g of water. The freezing point of the aqueous solution is _______ K. (in nearest integer)

(K$_f$ of water = 1.86 K kg mol$^{-1}$)

[Molar mass of C, H, O are 12, 1, 16 g mol$^{-1}$]

The value of $\mathbf x$ is ____.

The value of $|\mathbf y|$ is ____.

When 9.45 g of ClCH$_2$COOH is added to 500 mL of water, its freezing point drops by 0.5°C. The dissociation constant of ClCH$_2$COOH is $x\times10^{-3}$. The value of $x$ is _______. (Rounded off to the nearest integer)

[$K_{f(\mathrm{H_2O})}$ = 1.86 K kg mol$^{-1}$]

Liquids A and B form ideal solution for all compositions of A and B at 25 °C. Two such solutions with 0.25 and 0.50 mole fractions of A have the total vapor pressures of 0.3 and 0.4 bar, respectively. What is the vapor pressure of pure liquid B in bar?

On dissolving 0.5 g of a non-volatile non-ionic solute to 39 g of benzene, its vapor pressure decreases from 650 mm Hg to 640 mm Hg. The depression of freezing point of benzene (in K) upon addition of the solute is ______

(Given data: Molar mass and the molal freezing point depression constant of benzene are 78 g mol⁻¹ and 5.12 K kg mol⁻¹, respectively)

The mole fraction of urea in an aqueous urea solution containing 900 g of water is 0.05. If the density of the solution is 1.2 g cm⁻³, the molarity of urea solution is ______

(Given data: Molar masses of urea and water are 60 g mol⁻¹ and 18 g mol⁻¹, respectively)

Liquids A and B form ideal solution over the entire range of composition. At temperature T, equimolar binary solution of liquids A and B has vapour pressure 45 Torr. At the same temperature, a new solution of A and B having mole fractions $x_A$ and $x_B$, respectively, has vapour pressure of 22.5 Torr. The value of $x_A/x_B$ in the new solution is ______.

(given that the vapour pressure of pure liquid A is 20 Torr at temperature T)

The plot given below shows $P-T$ curves (where $P$ is the pressure and $T$ is the temperature) for two solvents X and Y and isomolal solutions of NaCl in these solvents. NaCl completely dissociates in both the solvents.

On addition of equal number of moles of a non-volatile solute S in equal amount (in kg) of these solvents, the elevation of boiling point of solvent X is three times that of solvent Y. Solute S is known to undergo dimerization in these solvents. If the degree of dimerization is 0.7 in solvent Y, the degree of dimerization in solvent X is ______.

For a solution formed by mixing liquids L and M, the vapour pressure of L plotted against the mole fraction of M in solution is shown in the following figure. Here $x_\mathrm{L}$ and $x_\mathrm{M}$ represent mole fractions of L and M, respectively, in the solution. The correct statement(s) applicable to this system is(are)

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 $2\ \mathrm{K\,kg\,mol^{-1}}$. The figures shown below represent plots of vapour pressure (V.P.) versus temperature (T). [molecular weight of ethanol is $46\ \mathrm{g\,mol^{-1}}$]

Among the following, the option representing change in the freezing point is

The freezing point of benzene decreases by 0.45°C when 0.2 g of acetic acid is added to 20 g of benzene. If acetic acid associates to form a dimer in benzene, percentage association of acetic acid in benzene will be :

($K_f$ for benzene = 5.12 K kg mol$^{-1}$)

5 g of $\ce{Na2SO4}$ was dissolved in $x$ g of $\ce{H2O}$. The change in freezing point was found to be 3.82°C. If $\ce{Na2SO4}$ is 81.5% ionised, the value of $x$ ($K_f$ for water = 1.86°C kg mol$^{-1}$) is approximately :

(molar mass of S = 32 g mol$^{-1}$ and that of Na = 23 g mol$^{-1}$)

A solution is prepared by mixing 8.5 g of $\ce{CH2Cl2}$ and 11.95 g of $\ce{CHCl3}$. If vapour pressure of $\ce{CH2Cl2}$ and $\ce{CHCl3}$ at 298 K are 415 and 200 mmHg respectively, the mole fraction of $\ce{CHCl3}$ in vapour form is :

(Molar mass of Cl = 35.5 g mol$^{-1}$)

Mixture(s) showing positive deviation from Raoult's law at 35 °C is(are)

18 g glucose ($\ce{C6H12O6}$) is added to 178.2 g water. The vapor pressure of water (in torr) for this aqueous solution is :

The solubility of $\ce{N2}$ in water at 300 K and 500 torr partial pressure is 0.01 g L$^{-1}$. The solubility (in g L$^{-1}$) at 750 torr partial pressure is :

An aqueous solution of a salt $\ce{MX2}$ at certain temperature has a van't Hoff factor of 2. The degree of dissociation for this solution of the salt is :

If the freezing point of a 0.01 molal aqueous solution of a cobalt(III) chloride-ammonia complex (which behaves as a strong electrolyte) is −0.0558 °C, the number of chloride(s) in the coordination sphere of the complex is

[$K_f$ of water = 1.86 K kg mol⁻¹]

The vapour pressure of acetone at 20°C is 185 torr. When 1.2 g of a non-volatile substance was dissolved in 100 g of acetone at 20°C, its vapour pressure was 183 torr. The molar mass (g mol$^{-1}$) of the substance is :