Surface Chemistry

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.

Assertion A: Finest gold is red in colour, as the size of the particles increases, it appears purple then blue and finally gold.

Reason R: The colour of the colloidal solution depends on the wavelength of light scattered by the dispersed particles.

In the light of the above statements, choose the most appropriate answer from the options given below.

Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R.

Assertion A: Activated charcoal adsorbs $\mathrm{SO_2}$ more efficiently than $\mathrm{CH_4}$.

Reason R: Gases with lower critical temperatures are readily adsorbed by activated charcoal.

In the light of the above statements, choose the correct answer from the options given below.

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A) : Dissolved substances can be removed from a colloidal solution by diffusion through a parchment paper.

Reason (R) : Particles in a true solution cannot pass through parchment paper but the colloidal particles can pass through the parchment paper.

In the light of the above statements, choose the correct answer from the options given below :

Match List - I with List - II.

Choose the correct answer from the options given below :

Among the following the number of curves not in accordance with Freundlich adsorption isotherm is ______.

100 mL of 5% (w/v) solution of NaCl in water was prepared in 250 mL beaker. Albumin from the egg was poured into NaCl solution and stirred well. This resulted in a/an :

Given below are the critical temperatures of some of the gases:

Gas	Critical temperature (K)
He	5.2
CH$_4$	190.0
CO$_2$	304.2
NH$_3$	405.5

The gas showing least adsorption on a definite amount of charcoal is

Freundlich's adsorption isotherm (in terms of concentration) is given by the expression; $\dfrac xm=K\cdot C^{1/n}$. The possible conclusions that can be drawn from the expression are :

(A) When $\frac1n=1$, the adsorption is directly proportional to concentration.

(B) When $\frac1n=0$, the adsorption is independent of concentration.

(C) When n = 0, a plot of x/m vs C is a line parallel to x-axis

(D) When n = 0, a plot of x/m vs C is a curve.

Choose the correct option from the following :

The correct statement(s) related to colloids is(are)

In Freundlich adsorption isotherm, slope of AB line is :

Molar conductivity $(\Lambda_m)$ of aqueous solution of sodium stearate, which behaves as a strong electrolyte, is recorded at varying concentrations $(c)$ of sodium stearate. Which one of the following plots provides the correct representation of micelle formation in the solution?

(critical micelle concentration (CMC) is marked with an arrow in the figures)

The correct statement(s) about surface properties is(are)

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.

Among the following, correct statement is :

Adsorption of a gas on a surface follows Freundlich adsorption isotherm. Plot of $\log\dfrac xm$ versus log p gives a straight line with slope equal to 0.5, then :

($\dfrac xm$ is the mass of the gas adsorbed per gram of adsorbent)

The qualitative sketches I, II and III given below show the variation of surface tension with molar concentration of three different aqueous solutions of KCl, $\ce{CH3OH}$ and $\ce{CH3(CH2)11OSO3^-Na+}$ at room temperature. The correct assignment of the sketches is

For a linear plot of log (x/m) versus log p in a Freundlich adsorption isotherm, which of the following statements is correct ? (k and n are constants)

A particular adsorption process has the following characteristics : (i) It arises due to van der Waals forces and (ii) it is reversible. Identify the correct statement that describes the above adsorption process :

The most appropriate method of making egg-albumin sol is :

Gold numbers of some colloids are : Gelatin : 0.005 - 0.01, Gum Arabic : 0.15 - 0.25; Oleate : 0.04 - 1.0; Starch : 15 - 25. Which among these is a better protective colloid ?