1421 + Interview Questions in SURFACE-CHEMISTRY IN GENERAL AWARENESS Page 8 InterviewSolution

351.	Substances which alter the velocity of a reaction by mere presence, without undergoing any change in mass and compossition are termed catalyst and the phenomenon is known as catalysis Which is incorrect for a catalyst?A. A catalyst can initiate a reaction.B. A catalyst remains uncharged in quality and composition at the end of reaction.C. It does not alter the position of equilibrium in a reversible reaction.D. Catalyst are sometimes very specific in reaction.
Answer» Correct Answer - A A catalyst cannot initiate reaction. Correct Answer - A A catalyst cannot initiate reaction.

Discussion

352.	Substances which alter the velocity of a reaction by mere presence, without undergoing any change in mass and compossition are termed catalyst and the phenomenon is known as catalysis For the reaction `(ArarrB+C)` , the energy profile diagram is given in the figure below. The decrease in ht eenergy of activation in hte presence of catalyst isA. ZB. `Z-P`C. `Y-Z`D. `Z-X`
Answer» Correct Answer - BCorrect Answer - B

Discussion

353.	Substances which alter the velocity of a reaction by mere presence, without undergoing any change in mass and compossition are termed catalyst and the phenomenon is known as catalysis According to the adsorption theroy of catalysis, the rate of reaction increases becauseA. According to the activation energy of the reaction.B. Concentration of reactant molecules at the active centres of the catalyst becomes high due to adsorption.C. Adsorption increases the activation energy of the reaction.D. Adsorption decreases the activation of the energy of the reaction.
Answer» Correct Answer - BCorrect Answer - B

Discussion

354.	`{:("Given",,,,),("Gas",H_(2),CH_(4),CO_(2),SO_(2)),("critical ",33,190,304,630):}` temperature /K ON the basic of data given above , predict which of the following gases shows least a dsorption on a definite amount of charcoal ?A. `CO_(2)`B. `SO_(2)`C. `CH_(4)`D. `H_(2)`
Answer» Correct Answer - D More the critical temperature for a gas, lesser will be the extent of adsorption.

Discussion

355.	The critical temperature of `SO_(2)` is 630 K and that of `CH_(4)` is 190 K . Which is adsorped easily on activated charcoal ? Why ?
Answer» Given the critical temperature of `SO_(2)` is 630 K and that of `CH_(4)` is 190 K. `SO_(2)` gas is adsorbed easily on activated charcoal because of higher critical temperature. Higher the critical temperature of gas, extent of adsorption is high.

Discussion

356.	`{:("Given",,,,),("Gas", H_(2), CH_(4), CO_(2), SO_(2)),("Critical", 33, 190, 304, 630),("Temperature "//K,,,,):}` On the basis of data given above, predict which of the following gases shows least adsorption on a definite amount of charcoal ?A. `CH_(4)`B. `H_(2)`C. `CO_(2)`D. `SO_(2)`
Answer» Correct Answer - B

Discussion

357.	Tyndall effect in colloidal solution is due toA. Reflection of lightB. Refraction of light polarisation of lightC. Scattering of lightD.
Answer» Correct Answer - D

Discussion

358.	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 particles 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.A. (b) and (d)B. (a) and (c)C. (b) and (c)D. (a) and (d)
Answer» Correct Answer - A

Discussion

359.	Tyndall effect in shown by :A. Charge on the collodial particleB. Osmotic pressure of colloidal solutionC. Difference between the refractive indices of dispersed phase and dispersion mediumD. Size of colloidal particles
Answer» Correct Answer - C

Discussion

360.	Tyndall effect is applicable whenA. The diameter of the dispersed particle is not much smaller than the wavelength of the light used.B. The diameter of the dispersed particles is much smaller than the wavelength of the light used.C. The refractive indices of the dispersed phase and the dispersed phase and the dispersion medium must be same.D. The refractive indices of the dispersed phase and the dispersion medium must differ greatly in magnitude.
Answer» Correct Answer - A::DCorrect Answer - A::D

Discussion

361.	Which of the following electrolytes will not be most effective in the coagulation of fold sol?A. `NaNO_(3)`B. `K_(4)[Fe(CN)_(6)]`C. `Na_(3)PO_(4)`D. `MgCl_(2)`
Answer» Correct Answer - A::B::C Gold sol is negatively charged. Hence, most effective for coagulation will be `Mg^(2+)` ions. Correct Answer - A::B::C Gold sol is negatively charged. Hence, most effective for coagulation will be `Mg^(2+)` ions.

Discussion

362.	Tyndall effect is applicable whenA. The diameter of the dispersed particle is not much smaller than the wavelength of the light used.B. The diameter of the dispersed particles is much smaller than the wavelength of the light used.C. The refractive indices of the dispersed phase and the dispersed phase and the dispersion medium must be same.D. The refractive indices of the dispersed phase and the dispersion medium must differ greatly in magnitude.
Answer» Correct Answer - A::DCorrect Answer - A::D

Discussion

363.	Which of the following are macromolecular colloids?A. StarchB. SoapC. DetergentD. Cellulose
Answer» Correct Answer - A::D Starch and cellulose are high molecular mass molecules. Correct Answer - A::D Starch and cellulose are high molecular mass molecules.

Discussion

364.	100 mL of 0.6 M acetic acid is shaken with 2 g activatid carbon . The final concetration solution after adsorption is 0.5 M. what is the amount of acetifc acid adsorbed per gram of carbon ?A. 0.6 gB. 0.3 gC. 1.2 gD. none of these
Answer» Correct Answer - b

Discussion

365.	Isoelectric point is the `pH` at which colloidal particlesA. CoagulateB. Becomes electrically neutral.C. Can move toward either electrodesD. None of these
Answer» Correct Answer - A::B::CCorrect Answer - A::B::C

Discussion

366.	1 L of 0.6 M acetic acid is shaken with 2 g activated carbon. Activated carbon adsorbs some acetic acid on its surface only. This process is called adsorption. The final concentration of the solution after adsorption is 0.5 M. What is the amount of acetic acid adsorbed per gram of carbon.
Answer» Correct Answer - `03` Mass of acetic acid adsorbed `= (0.6 - 0.5) xx 1 xx 60 = 6 g` Mass of acetic acid adsorbed per gram of carbon `= (6)/(2) = 3 g`

Discussion

367.	The example of heteropolar sol. isA. Starch sol in waterB. Rubber sol in waterC. Protein sol in waterD. It is not very stable in a solvent
Answer» Correct Answer - C Protein sol in water is a example of heteropolar sol.

Discussion

368.	At isoelectric pointA. Colloidal sol becomes highly stableB. Precipitation of a colloidal sol takes placeC. Colloidal particles becomes unchargedD. Peptization can be carried out
Answer» Correct Answer - C Colloidal particls becomes uncharged at isoelectric point.

Discussion

369.	Pd can adsorb 900 times its volume of hydrogen. This is called :-A. AbsorptionB. AdsorptionC. OcclusionD. 2 & 3 both
Answer» Correct Answer - D

Discussion

370.	Although nitrogen does not adsorb on surface at room temperature, it adsorbs on the same surface at `83K` . Which one of the following statements is correct?A. At 83 K there is formation of MonolayerB. At 83 K , nitrogen is adsorbed as atomsC. At 83 K , nitrogen molecules are held by chemical bondsD. At 83 K, there is formation of multimolecular layers
Answer» Correct Answer - d

Discussion

371.	which of the following is used to adsorb water ?A. silica gelB. Calcium acetateC. Hair gelD. Anhydrous `CaCl_(2)`
Answer» Correct Answer - a

Discussion

372.	Metals like Pt and Pd can adsorb large volume of hydrogen under specific conditions. Such adsorbed hydrogen by the metal is known asA. Occluded hydrogenB. Absorbed hydrogenC. Reactive hydrogenD. Atomic hydrogen
Answer» Correct Answer - A

Discussion

373.	Assertion: When `AgNO_(3)` is treated with excess of `Kl`, colloidal particles gets attracted towards anode. Reason: Colloidal particles adsorb common ions and thus becomes charged.A. Statement-1 is True, Statement-2 is True, Statement-2 is a correct explanation for Statement-1.B. Statement-1 is True, Statement-2 is True, Statement-2 is NOT a correct explanation for Statement-1.C. Statement-1 isTrue, Statement-2 is False.D. Statement-1 is False, Statement-2 is True.
Answer» Correct Answer - A

Discussion

374.	The Langmuir adsorption isotherm is deduced using the assumption.A. The adsoption takes place in multilayersB. the adsorption sites are equivalent in their ability to adsorb the particleC. The heat of adsorption varies with coverageD. The adsorbed molecules interact with each other
Answer» Correct Answer - B Every adsorption site is equivaelent and the ability of the gas molecule to bound there is independent of whether the neighbouring sites are occupied or not.

Discussion

375.	Dyeing of filber involves the process of :A. adsorptionB. absorptonC. sorptonD. all of these
Answer» Correct Answer - D It involves sorpton involving both process fo absorption and adsorption taking place simultaneously .

Discussion

376.	If `x` is the amount of adsorbate and `m` is the amount of adsorbent, which of the following relation is related to adsorption process?A. `(x)/(m)=pxxT`B. `(x)/(m)=f(p)` at constant `T`C. `(x)/(m)=f(T)` at constant `P`D. `p=f(T)` at constant `(x//m)`
Answer» Correct Answer - A According to adsorption isobar `(x//m)` is a function of temperature `(T)` at constant `P` . According to adsorption isotherm, `(x//m)` is a functions of pressure `(P)` at constant temperature `(T)` . According to adsoption isostere, a linear relationship exists between temperature and pressure at constant `(x//m)` . Thus, `x//m=PxxT` , is not related to adsorption process. The correct relation is `(x)/(m)prop(P)/(T)`

Discussion

377.	Which can adsorb largr velume of hydrogen fas ?A. Colloidal solution of palladiumB. Finely divede nickelC. Finely divided platinumD. Collidal ` Fe (OH)_3`
Answer» Correct Answer - A Due to maximum surface area in colloidal state .

Discussion

378.	Which one is not the characteristioc of chemnisorption ?A. Multilayer assorptonB. Exothermic in natureC. Strong assorpton by free valenciesD. Irreversible
Answer» Correct Answer - A Chemisorpton is unilayer adsorption.

Discussion

379.	The Langmuir adsorption isotherm is deduced using the assumption.A. The heat of adsorption varies with coverageB. The adsorbed molecules interact with each otherC. The adsorption takes place in multilayers.D. The adsorption sites are equivalent in their ability to adsob the particles.
Answer» Correct Answer - D Langmuir adsorption isotherm is based on the assumption that every adsorption site is equivalent and that the ability of a particle to bind there is independent of whether or not nearby sites are occupied.

Discussion

380.	A plt of log `X/m` vs. log P for the adsorption of a gasd on a solid gives a straight line with slope equal to :A. ` 1//n`B. `ln K`C. `-log K`D. `n`
Answer» Correct Answer - A According ot Freundlich ` X/m = K (P)^(1//2)` `:. log X/m = log K+ 1/n log (P)` ` y = C+ m x` ` :. m = "slope" = 1/n.

Discussion

381.	Which one of the following forms micells in aqueous solution above certain concentration?A. GlucoseB. UreaC. Dodecy trimethyl ammonium chlorideD. Pyridinimum chlroide
Answer» Correct Answer - C When molecules or ions that have both a hydrophobic and a hydrophilic end are dispersed in water, they associate or aggregate to from colloidal sized particles called micelles. Micelle is a colloidal-sized particles or ions that each have a hydrophobic end and a hydrophilic end. The hydrophobic ends point inward toward one another and hydrophilic ends are non the outside of the micelle facing the water. A colloidal in which the dispersed phase consists of micelles is called an associated colloid. Dodecyl trimethyl ammonium chloride (a cationic surfactant) in water provides an example of an association colloid which forms micelles (positively charged) above its `CMC` ,

Discussion

382.	A plt of log `X/m` vs. log P for the adsorption of a gasd on a solid gives a straight line with slope equal to :A. `K`B. `log K`C. In `K`D. `1//n`
Answer» Correct Answer - D ` log .x/m = log K + 1/n P, ` thus is Freundillisch isotherm . Thus slope `= 1/n`.

Discussion

383.	For adsorption of a gas on a solid, the plot of log (x/m) Vs log P is linear with a slope equal to : [n being a whole number]A. KB. log kC. nD. 1/n
Answer» Correct Answer - D `(x)/(m) = KP^(1//n), " " "log " (x)/(m) = "log " K + (1)/(n) " log " P`

Discussion

384.	In the formation of `SO_3 by `: `2 SO_2 + O_2 overset (NO) (rarr) 2 SO_3`, the catalytic action of ` NO` is evidenced by the formation of :A. brown vapoursB. green vapoursC. wiolet vapoursD. none of these
Answer» Correct Answer - A `MO` forms ` NO_2` as an intermediate .

Discussion

385.	Suspension of slaked lime in water is known asA. limewaterB. quicklimeC. milk of limeD. aqueous solution of slaked lime
Answer» Correct Answer - C Aqueous solution of slaked lime is called lime water whereas suspension solution of slaked lime is called milk of lime.

Discussion

386.	How do emulsifiers stabilize emulsion ? Name two emulsifiers.
Answer» Emulsifying agent : The third substance which is added in small amounts to an emulsion to stabilize the emulsion is called emulsifying agent. `to` The emulsifying agent forms an interfacial film between suspended particles and the medium. Eg : 1) Carbon black stabilizes water in oil type emulsions. 2) Casein and silica stabilize oil in water type emulsions.

Discussion

387.	Which type of compound can form micelles? Give example
Answer» Compound must contain polar head and non-polar tail e.g. soap and synthetic detergent.

Discussion

388.	In which of the following Tyndall effect is not observedA. sugar solutionB. gold solutionC. suspensionD. emulsion
Answer» Correct Answer - A Tyndal effect is not observed in sugar solution.

Discussion

389.	Which is kinetic phenomenon ?A. Brownian motionB. Tyndall effectC. Both a. and b .D. None of these
Answer» Correct Answer - A Brawnian motion is the kinetic phenomenon.

Discussion

390.	Which of the following sols is hydrophobic ?A. StarchB. GumC. SulphurD. Gelatin
Answer» Correct Answer - C Sulphur sol is hydrophobic .

Discussion

391.	Difine ultrafiltration.
Answer» In this process, colloidal solutions are purified by carrying out filtration throuh special types of graded filters called ultra-filters. Filter paper allows the passage of electrolyte but does not allow the passage of colloidal particles. In this process, colloidal solutions are purified by carrying out filtration throuh special types of graded filters called ultra-filters. Filter paper allows the passage of electrolyte but does not allow the passage of colloidal particles.

Discussion

392.	Which of the following is/are elastic gel?A. GelatinB. Silicic acidC. Agar agarD. Starch
Answer» Correct Answer - A::C::D Silicic acid is a non-elastic gel. Correct Answer - A::C::D Silicic acid is a non-elastic gel.

Discussion

393.	Which of the following is/are negatively charged sol?A. Gold solB. Prussian blue dyeC. HaemolobinD. Starch
Answer» Correct Answer - A::DCorrect Answer - A::D

Discussion

394.	Which of the following is/are aerosols?A. SmokeB. MilkC. ButterD. Fog
Answer» Correct Answer - A::D Milk is emulsion, butter is gel. Smoke and fog have gas (air) as the dispersion medium and hence are aerosol. Correct Answer - A::D Milk is emulsion, butter is gel. Smoke and fog have gas (air) as the dispersion medium and hence are aerosol.

Discussion

395.	Which of following are examples of aerosols ?A. Whipped creamB. CloudC. FogD. starch solution
Answer» Correct Answer - B::C are aerosols in nature.

Discussion

396.	If `Cl_(2)` gas is enclosed in presence of powdered charcoal in a closed vessel, the pressure of the gas decreases. It is because :A. the gas molecules are absorbed at the surfaceB. the gas molecules concentrate at the surface of the charcoalC. the gas molecules are adsorbed at the surfaceD. the gas molecules are desorbed by the surface
Answer» Correct Answer - B::C

Discussion

397.	If `Cl_(2)` gas is enclosed in presence of powdered charcoal in a closed vessel, the pressure of the gas decreases. It is because :A. the gas molecules are adsorbed at the surfaceB. the gas molecules concentrate at the surface of the charcoalC. the gas molecules are adsorbed at the surfaceD. the gas molecules are desorbed by the surface
Answer» Correct Answer - B::C This is because of absorption.

Discussion

398.	Give two examples of colloidal solution of liquid dispersed in solid. What is the name of the colloidal solution?
Answer» Jelly, cheese. The name of these colloidal solutions is gel. Jelly, cheese. The name of these colloidal solutions is gel.

Discussion

399.	What is observed when sodium chloride is added to a colloidal solution of ferric hydroxide?
Answer» When sodium chloride is added to ferric hydroxide solution gets coagulated. This is because `Cl^(ɵ)` ions from `NaCl` neutralize the `+ve` charge on `Fe(OH)_(3)` solution.When sodium chloride is added to ferric hydroxide solution gets coagulated. This is because `Cl^(ɵ)` ions from `NaCl` neutralize the `+ve` charge on `Fe(OH)_(3)` solution.

Discussion

400.	Colloidal solution can be purified by :A. Dialysis electrodialysisB. ElectrophoresisC. UltrafiltrationD.
Answer» Correct Answer - A::B::D Dialysis, electrodialysis and ultrafiltration are used for purification of colloidal solution.

Discussion

Explore topic-wise InterviewSolutions in .

`{:("Given",,,,),("Gas",H_(2),CH_(4),CO_(2),SO_(2)),("critical ",33,190,304,630):}` temperature /K ON the basic of data given above , predict which of the following gases shows least a dsorption on a definite amount of charcoal ?A. `CO_(2)`B. `SO_(2)`C. `CH_(4)`D. `H_(2)`

The critical temperature of `SO_(2)` is 630 K and that of `CH_(4)` is 190 K . Which is adsorped easily on activated charcoal ? Why ?

`{:("Given",,,,),("Gas", H_(2), CH_(4), CO_(2), SO_(2)),("Critical", 33, 190, 304, 630),("Temperature "//K,,,,):}` On the basis of data given above, predict which of the following gases shows least adsorption on a definite amount of charcoal ?A. `CH_(4)`B. `H_(2)`C. `CO_(2)`D. `SO_(2)`

Tyndall effect in colloidal solution is due toA. Reflection of lightB. Refraction of light polarisation of lightC. Scattering of lightD.

Tyndall effect in shown by :A. Charge on the collodial particleB. Osmotic pressure of colloidal solutionC. Difference between the refractive indices of dispersed phase and dispersion mediumD. Size of colloidal particles

Which of the following electrolytes will not be most effective in the coagulation of fold sol?A. `NaNO_(3)`B. `K_(4)[Fe(CN)_(6)]`C. `Na_(3)PO_(4)`D. `MgCl_(2)`

Which of the following are macromolecular colloids?A. StarchB. SoapC. DetergentD. Cellulose

100 mL of 0.6 M acetic acid is shaken with 2 g activatid carbon . The final concetration solution after adsorption is 0.5 M. what is the amount of acetifc acid adsorbed per gram of carbon ?A. 0.6 gB. 0.3 gC. 1.2 gD. none of these

Isoelectric point is the `pH` at which colloidal particlesA. CoagulateB. Becomes electrically neutral.C. Can move toward either electrodesD. None of these

1 L of 0.6 M acetic acid is shaken with 2 g activated carbon. Activated carbon adsorbs some acetic acid on its surface only. This process is called adsorption. The final concentration of the solution after adsorption is 0.5 M. What is the amount of acetic acid adsorbed per gram of carbon.

The example of heteropolar sol. isA. Starch sol in waterB. Rubber sol in waterC. Protein sol in waterD. It is not very stable in a solvent

At isoelectric pointA. Colloidal sol becomes highly stableB. Precipitation of a colloidal sol takes placeC. Colloidal particles becomes unchargedD. Peptization can be carried out

Pd can adsorb 900 times its volume of hydrogen. This is called :-A. AbsorptionB. AdsorptionC. OcclusionD. 2 & 3 both

which of the following is used to adsorb water ?A. silica gelB. Calcium acetateC. Hair gelD. Anhydrous `CaCl_(2)`

Metals like Pt and Pd can adsorb large volume of hydrogen under specific conditions. Such adsorbed hydrogen by the metal is known asA. Occluded hydrogenB. Absorbed hydrogenC. Reactive hydrogenD. Atomic hydrogen

The Langmuir adsorption isotherm is deduced using the assumption.A. The adsoption takes place in multilayersB. the adsorption sites are equivalent in their ability to adsorb the particleC. The heat of adsorption varies with coverageD. The adsorbed molecules interact with each other

Dyeing of filber involves the process of :A. adsorptionB. absorptonC. sorptonD. all of these

If `x` is the amount of adsorbate and `m` is the amount of adsorbent, which of the following relation is related to adsorption process?A. `(x)/(m)=pxxT`B. `(x)/(m)=f(p)` at constant `T`C. `(x)/(m)=f(T)` at constant `P`D. `p=f(T)` at constant `(x//m)`

Which can adsorb largr velume of hydrogen fas ?A. Colloidal solution of palladiumB. Finely divede nickelC. Finely divided platinumD. Collidal ` Fe (OH)_3`

Which one is not the characteristioc of chemnisorption ?A. Multilayer assorptonB. Exothermic in natureC. Strong assorpton by free valenciesD. Irreversible

The Langmuir adsorption isotherm is deduced using the assumption.A. The heat of adsorption varies with coverageB. The adsorbed molecules interact with each otherC. The adsorption takes place in multilayers.D. The adsorption sites are equivalent in their ability to adsob the particles.

A plt of log `X/m` vs. log P for the adsorption of a gasd on a solid gives a straight line with slope equal to :A. ` 1//n`B. `ln K`C. `-log K`D. `n`

Which one of the following forms micells in aqueous solution above certain concentration?A. GlucoseB. UreaC. Dodecy trimethyl ammonium chlorideD. Pyridinimum chlroide

A plt of log `X/m` vs. log P for the adsorption of a gasd on a solid gives a straight line with slope equal to :A. `K`B. `log K`C. In `K`D. `1//n`

For adsorption of a gas on a solid, the plot of log (x/m) Vs log P is linear with a slope equal to : [n being a whole number]A. KB. log kC. nD. 1/n

In the formation of `SO_3 by `: `2 SO_2 + O_2 overset (NO) (rarr) 2 SO_3`, the catalytic action of ` NO` is evidenced by the formation of :A. brown vapoursB. green vapoursC. wiolet vapoursD. none of these

Suspension of slaked lime in water is known asA. limewaterB. quicklimeC. milk of limeD. aqueous solution of slaked lime

How do emulsifiers stabilize emulsion ? Name two emulsifiers.

Which type of compound can form micelles? Give example

In which of the following Tyndall effect is not observedA. sugar solutionB. gold solutionC. suspensionD. emulsion

Which is kinetic phenomenon ?A. Brownian motionB. Tyndall effectC. Both a. and b .D. None of these

Which of the following sols is hydrophobic ?A. StarchB. GumC. SulphurD. Gelatin

Difine ultrafiltration.

Which of the following is/are elastic gel?A. GelatinB. Silicic acidC. Agar agarD. Starch

Which of the following is/are negatively charged sol?A. Gold solB. Prussian blue dyeC. HaemolobinD. Starch

Which of the following is/are aerosols?A. SmokeB. MilkC. ButterD. Fog

Which of following are examples of aerosols ?A. Whipped creamB. CloudC. FogD. starch solution

Give two examples of colloidal solution of liquid dispersed in solid. What is the name of the colloidal solution?

What is observed when sodium chloride is added to a colloidal solution of ferric hydroxide?

Colloidal solution can be purified by :A. Dialysis electrodialysisB. ElectrophoresisC. UltrafiltrationD.