41.

For an ideal binary liquid solution with ${\mathrm{p}}_{\mathrm{x}}^0 > {\mathrm{p}}_{\mathrm{y}}^0$ in which relation between X_x (mole fraction of X in liquid phase) and Y_x ( mole fraction of Y in liquid and vapour phase respectively.

• X_x > Y_X

• X_x = Y_x

• $\frac{{\mathrm{X}}_{\mathrm{X}}}{{\mathrm{X}}_{\mathrm{Y}}} < \frac{{\mathrm{Y}}_{\mathrm{X}}}{{\mathrm{Y}}_{\mathrm{Y}}}$

• X_X, Y_X, X_Y and Y_Y cannot be correlated

Point out the incorrect reaction from the following.

• 2Na₂CrO₄ + H⁺ $\to$ Na₂Cr₂O₇ + 2Na⁺ + H₂O

• 4MnO₂ + 4KOH + O₂ $\to$ 4KMnO₄ + 2H₂O

• 2Mn${\mathrm{O}}_4^{-}$ + 5C₂${\mathrm{O}}_4^{2-}$ + 16H⁺ $\to$ 2Mn²⁺ + 10CO₂ + 8H₂O

• Mn${\mathrm{O}}_4^{-}$ + 8H⁺ + 5Fe²⁺ $\to$5Fe³⁺ + Mn²⁺ + 4H₂O

The conductivity of 0.001028 mol L^-1 acetic acid is 4.95 x 10^-5 S cm^-1. Find out its dissociation constant if Λ_m for acetic acid is 390.5 S cm^-1 mol^-1.

• 2.18 x 10^-5 mol^-1L^-1

• 1.78 x 10^-5 mol L^-1

• 3.72 x 10^-4 mol L^-1

• 2.37 x 10^-4 mol L^-1

A hypothetical reaction

X₂ + Y₂ $\to$2XY follows the following mechanism

X₂ $\rightleftharpoons$ X + X .... fast

X + Y₂ $\to$ XY + Y .... slow

X + Y $\to$XY .... fast

The order of overall reaction is

• 2

• $\raisebox{1ex}{$3$}\!\left/ \!\raisebox{-1ex}{$2$}\right.$

• 1

• 0

The major role of fluorspar (CaF₂) which is added in small quantity in the electrolytic reduction of alumina dissolved in fused cryolite (Na₃AlF₆) is

I. as a catalyst.

II. to make the fused mixture very conducting.

III. to lower the temperature of melting.

IV. to decrease the rate of oxidation of carbon at the anode.

• I, II

• II, III

• I, II, III

• III, IV

The variation of concentration of the product P with time in the reaction, A $\to$ P is shown in following graph.

The graph between $\frac{-d \left[A\right]}{dt}$ and time will be of the type

Which of the following represents physical adsorption?

In an experiment, addition of 4.0 mL of 0.005 M BaCl₂ to 16.0 mL of arsenious sulphide sol just causes complete coagulation in 2 h. The flocculating value of the effective ion is

• Ba²⁺, 1.0

• Ba²⁺, 2.0

• Cl^-, 1.0

• Cl^-, 2.0

The aqueous solution of an unknown sodium salt gives the following reactions.

I. It decolourises a solution of iodine in potassium iodide.

II. It gives white turbidity with dil.HCl solution.

III. It gives a white precipitate with AgNO₃ solution which changes colours and finally becomes black on standing.

The unknown sodium salt is

• Sodium thiosulphate

• sodium bisulphite

• sodium sulphite

• sodium sulphide

The suitable reaction steps to carry out the following transformation is

• $\underset{\left(\mathrm{ii}\right) {\mathrm{H}}_2{\mathrm{O}}_2, \mathrm{NaOH}}{\overset{\left(\mathrm{i}\right) {\mathrm{BH}}_3, \mathrm{THF}}{\to }} \stackrel{{\mathrm{HIO}}_4}{\to }$

• $\underset{({\mathrm{CH}}_3{)}_3\mathrm{C}.\mathrm{COOH}, {\mathrm{OH}}^{-}}{\overset{{\mathrm{OsO}}_4}{\to }} \underset{{\mathrm{H}}_2\mathrm{O}}{\overset{{\mathrm{K}}_3{\mathrm{Cr}}_2{\mathrm{O}}_7.{\mathrm{H}}_2{\mathrm{SO}}_4}{\to }}$

• $\underset{\left(\mathrm{ii}\right) {\mathrm{H}}_2{\mathrm{O}}_2, \mathrm{NaOH}}{\overset{\left(\mathrm{i}\right) {\mathrm{BH}}_3, \mathrm{THF}}{\to }} \underset{{\mathrm{CH}}_2{\mathrm{Cl}}_2}{\overset{\mathrm{PCC}}{\to }}$

• $\stackrel{{\mathrm{H}}_2\mathrm{O}, {\mathrm{H}}_2{\mathrm{SO}}_4 \left(\mathrm{dil}\right)}{\to } \underset{{\mathrm{CH}}_2{\mathrm{Cl}}_2}{\overset{\mathrm{PCC}}{\to }}$