Surface Chemistry · Chemistry · JEE Main

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 :

'Adsorption' principle is used for which of the following purification method?

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 directions when the size of particles is large enough.

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

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

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

Ferric chloride is applied to stop bleeding because -

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

Which of the following represent the Freundlich adsorption isotherms?

Choose the correct answer from the options given below:

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

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

Assertion A: Amongst $$\mathrm{He}, \mathrm{Ne}, \mathrm{Ar}$$ and $$\mathrm{Kr}$$; 1$$\mathrm{g}$$ of activated charcoal adsorbs more of $$\mathrm{Kr}$$.

Reason R: The critical volume $$\mathrm{V}_{\mathrm{c}}\left(\mathrm{cm}^{3} \mathrm{~mol}^{-1}\right)$$ and critical pressure $$\mathrm{P}_{\mathrm{c}}$$ (atm) is highest for Krypton but the compressibility factor at critical point $$\mathrm{Z}_{\mathrm{c}}$$ is lowest for Krypton.

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:

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

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 air via adsorption, thus protects the instrument from water corrosion (rusting) and / or prevents malfunctioning.

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

Match List I and List II

Choose the correct answer from the options given below :

Which of the following salt solutions would coagulate the colloid solution formed when $$\mathrm{FeCl_3}$$ is added to $$\mathrm{NaOH}$$ solution, at the fastest rate?

The variation of the rate of an enzyme catalyzed reaction with substrate concentration is correctly represented by graph :

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 same charges is called the electrokinetic potential or zeta potential.

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

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

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

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

Match List - I with List - II.

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 :

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.

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.

TLC analysis of a mixture having 3 components (A, B, C) using silica gel as the stationary phase gave following R_f values; for A = 0.72, B = 0.48, C = 0.20.

Regarding the above observations, which one of the following statements is not correct for column chromatography of the mixture?

A 42.12% (w/v) solution of NaCl causes precipitation of a certain sol in 10 hours. The coagulating value of NaCl for the sol in 2 hours is :

[Given : Molar mass : Na = 23.0 g mol^$$-$$1 ; Cl = 35.5 g mol^$$-$$1]

Which of the following is a correct statement?

Match List - I with List - II :

Choose the correct answer from the options given below:

The Zeta potential is related to which property of colloids?

Match List-I with List-II

Choose the correct answer from the options given below :

Incorrect statement for Tyndall effect is :

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

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 appropriate answer from the options given below :

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 catalyst's surface through formation of an intermediate.

D. It is a combination of intermediate compound formation theory and the old adsorption theory.

E. It explains the action of the catalyst as well as those of catalytic promoters and poisons.

Coagulating value of the electrolytes $$\mathrm{AlCl}_{3}$$ and $$\mathrm{NaCl}$$ 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 $$\mathrm{NaCl}$$. The value of $$\underline{x}$$ is ___________.

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

For the adsorption of hydrogen on platinum, the activation energy is $$30 ~\mathrm{k} ~\mathrm{J} \mathrm{mol}^{-1}$$ and for the adsorption of hydrogen on nickel, the activation energy is $$41.4 ~\mathrm{k} ~\mathrm{J} \mathrm{mol}^{-1}$$. The logarithm of the ratio of the rates of chemisorption on equal areas of the metals at $$300 \mathrm{~K}$$ is __________ (Nearest integer)

Given: $$\ln 10=2.3$$

$$\mathrm{R}=8.3 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$$

Based on the given figure, the number of correct statement/s is/are __________.

A. Surface tension is the outcome of equal attractive and repulsive forces acting on the liquid molecule in bulk.

B. Surface tension is due to uneven forces acting on the molecules present on the surface.

C. The molecule in the bulk can never come to the liquid surface.

D. The molecules on the surface are responsible for vapour pressure if the system is a closed system.

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, $$\Delta$$H becomes more and more negative.

D. Adsorption is accompanied by decrease in entropy of the system.

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

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

(a)

(b)

(c)

(d)

100 mL of 0.3 M acetic acid is shaken with 0.8 g of wood charcoal. The final concentration of acetic acid in the solution after adsorption is 0.125 M. The mass of acetic acid adsorbed per gram of carbon is _____________ $$\times$$ 10^$$-$$4 g.

(Given : Molar mass of acetic acid = 60 g mol^$$-$$1)

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 g.

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.