Surface Chemistry — JEE Main PYQs

The adsorbent used in adsorption chromatography is/are
A. silica gel
B. alumina
C. quick lime
D. magnesia

Choose the most appropriate answer from the options given below :

Identity the incorrect pair from the following:

For the adsorption of hydrogen on platinum, the activation energy is $30\mathrm{kJ}{\mathrm{mol}}^{-1}$ and for the adsorption of hydrogen on nickel, the activation energy is $41.4\mathrm{kJ}{\mathrm{mol}}^{-1}$. The logarithm of the ratio of the rates of chemisorption on equ …

The number of colloidal systems from the following, which will have 'liquid' as the dispersion medium, is ____

Gem stones, paints, smoke, cheese, milk, hair cream, insecticide sprays, froth, soap lather.

Coagulating value of electrolytes ${\mathrm{AlCl}}_3$ and NaCl for ${\mathrm{As}}_2{\mathrm{S}}_3$ are 0.09 and 50.04 respectively. The coagulating power of ${\mathrm{AlCl}}_3$ is $x$ times the coagulating power of NaCl . The value of $x$ is
____ :

Ferric chloride is applied to stop bleeding because:

Which of the following represent the Freundlich adsorption isotherms?
(A)
(B)
(C)
(D)

Choose the correct answer from the options given below:

The enthalpy change for the adsorption process and micelle formation respectively are

The number of correct statements about modern adsorption theory of heterogeneous catalysis from the following is ______
A. The catalyst is diffused over the surface of reactants.
B. Reactants are adsorbed on the surface of the catalyst.
C. Occurrence of chemical reaction on the c …

Four gases A, B, C and D have critical temperatures 5.3, 33.2, 126.0 and 154.3 K respectively.
For their adsorption on fixed amount of charcoal, the correct order is :

What happens when a lyophilic sol is added to a lyophobic sol?

Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A : The diameter of colloidal particles in solution should not be much smaller than wavelength of light to show Tyndall effect.
Reason R : The light scatters in all dir …

20 mL of 0.5 M NaCl is required to coagulate 200 mL of ${\mathrm{As}}_2{\mathrm{S}}_3$ solution in 2 hours. The coagulating value of NaCl is ______

Statement I: For colloidal particles, the values of colligative properties are of small order as compared to values shown by true solutions at same concentration.

Statement II : For colloidal particles, the potential difference between the fixed layer and the diffused layer of s …

The number of statement/s which are the characteristics of physisorption is ______.
A. It is highly specific in nature
B. Enthalpy of adsorption is high
C. It decreases with increase in temperature
D. It results into unimolecular layer
E. No activation energy is needed

The number of incorrect statement/s from the following is/are ____
A. Water vapours are adsorbed by anhydrous calcium chloride.
B. There is a decrease in surface energy during adsorption.
C. As the adsorption proceeds, $\Delta \mathrm{H}$ becomes more and more negative.
D. …

Which of the following salt solutions would coagulate the colloid solution formed when ${\mathrm{FeCl}}_3$ is added to NaOH solution, at the fastest rate?

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

Assertion (A) : In expensive scientific instruments, silica gel is kept in watch-glasses or in semipermeable membrane bags.

Reason (R) : Silica gel adsorbs moisture from a …

In figure, a straight line is given for Freundlich Adsorption $(y=3x+2.505)$. The value of $\frac{1}{\mathrm{n}}$ and $\log \mathrm{K}$ are respectively.

The graph of $\log \frac{\mathrm{X}}{\mathrm{m}}$ vs $\log \mathrm{p}$ for an adsorption process is a straight line inclined at an angle of $45^{\circ }$ with intercept equal to 0.6020. The mass of gas adsorbed per unit mass of adsorbent at the pressure of 0.4 atm is ______ …

Adding surfactants in non polar solvent, the micelles structure will look like

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

The gas showing least adsorption on a …

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

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 char …

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.
Assertion R : The colour of the colloidal solut …

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 thro …

For micelle formation, which of the following statements are correct?
(A) Micelle formation is an exothermic process.
(B) Micelle formation is an endothermic process.
(C) The entropy change is positive.
(D) The entropy change is negative.

Match List - I with List - II.

List - I
(Processes/Reactions)
(A) 2SO₂(g) + O₂(g) → 2SO₃(g)
(B) 4NH₃(g) + 5O₂(g) → 4NO(g) + 6H₂O(g)
(C) N₂(g) + 3H₂(g) → 2NH₃(g)
(D) Vegetable oil (l) + H₂ → Vegetable ghee(s)

List - II
(Catalyst)
(I) Fe(s)
(II) Pt(s)-Rh(s)
(III) V₂O₅
(IV) Ni(s) …

If the initial pressure of a gas is 0.03 atm, the mass of the gas adsorbed per gram of the adsorbent is ______ $\times 10^{-2}\mathrm{g}$.

The Zeta potential is related to which property of colloids?

Which of the following is a correct statement?

2.0 g of ${\mathrm{H}}_2$ gas is adsorbed on 2.5 g of platinum powder at 300 K and 1 bar pressure. The volume of the gas adsorbed per gram of the adsorbent is
____ mL.
(Given : $\mathrm{R}=0.083\mathrm{L}$ bar ${\mathrm{K}}^{-1}{\mathrm{mol}}^{-1}$ )

Match List-I with List-II

List-I:
(A) Lyophilic colloid
(B) Emulsion
(C) Positively charged colloid
(D) Negatively charged colloid

List-II:
(I) Liquid-liquid colloid
(II) protective colloid
(III) ${\mathrm{FeCl}}_3+\mathrm{NaOH}$
(IV) ${\mathrm{FeCl}}_3+$ hot water

Choose the …

100 mL of $5\%(\mathrm{w}/\mathrm{v})$ 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 two statements :

Statement I : Emulsions of oil in water are unstable and sometimes they separate into two layers on standing.

Statement II :For stabilisation of an emulsion, excess of electrolyte is added.

In the light of the above statements, choose the most …

When 200 mL of 0.2 M acetic acid is shaken with 0.6 g of wood charcoal, the final concentration of acetic acid after adsorption is 0.1 M. The mass of acetic acid adsorbed per gram of carbon is _____ g.

Incorrect statement for Tyndall effect is :-

Using very little soap while washing clothes, does not serve the purpose of cleaning of clothes because

In Freundlich adsorption isotherm, slope of AB line is :

Which one of the following is correct for the adsorption of a gas at a given temperature on a solid surface?

The sol given below with negatively charged colloidal particles is:

The conditions given below are in the context of observing Tyndall effect in colloidal solutions:
(a) The diameter of the colloidal particles is comparable to the wavelength of light used.
(b) The diameter of the colloidal particles in much smaller than the wavelength of light us …

Most suitable salt which can be used for efficient clotting of blood will be:

100 ml of $0.0018\%(\mathrm{w}/\mathrm{v})$ solution of ${\mathrm{Cl}}^{-}$ion was the minimum concentration of ${\mathrm{Cl}}^{-}$required to precipitate a negative sol in one h . The coagulating value of ${\mathrm{Cl}}^{-}$ion is ____ . (Nearest integer)

Lyophilic sols are more stable than lyophobic sols because :

In Freundlich adsorption isotherm at moderate pressure, the extent of adsorption $\left(\frac{x}{m}\right)$ is directly proportional to ${\mathrm{P}}^{\mathrm{x}}$. The value of x is :

When silver nitrate solution is added to potassium iodide solution then the sol produced is:

3.12 g of oxygen is adsorbed on 1.2 g of platinum metal. The volume oxygen adsorbed per gram of the adsorbent at 1 atm and 300 K in L is ______
$\left[\mathrm{R}=0.0821\mathrm{L}\mathrm{atm}{\mathrm{K}}^{-1}{\mathrm{mole}}^{-1}\right]$

Tyndall effect is more effectively shown by:

The nature of charge on resulting colloidal particles when ${\mathrm{FeCl}}_3$ is added to excess of hot water is: