1421 + Interview Questions in SURFACE-CHEMISTRY IN GENERAL AWARENESS Page 11 InterviewSolution

501.	Freundlich isotherm explains the behaviour of adsorptionA. CorrectlyB. ApproximatelyC. WronglyD. At very high temperature only
Answer» Correct Answer - B

Discussion

502.	Which of the following is correct regarding adsorption ?A. `DeltaG` is negative, but `DeltaH` and `DeltaS` are positiveB. `DeltaG` and `DeltaH` are negative, but `DeltaS` is positiveC. `DeltaG` and `DeltaS` are negative, but `DeltaH` is positiveD. `DeltaG` , `DeltaH` , and `DeltaS` are alll negative
Answer» Correct Answer - D Adsorption generally occurs with release of energy i.e., it is exothermic in nuture. A spontanceous process like adsorption requires a negative `DeltaG` . Since the translational freedom of the adsorbae is reduced when it is adsobed, `DeltaS` is generally negative.

Discussion

503.	What is meant by chemical adsorption?
Answer» If the adsorbate is held on a dsurface of the adsorption as a resuslt of chemical reaction foming surface compounds, it is called chemical adsorption If the adsorbate is held on a dsurface of the adsorption as a resuslt of chemical reaction foming surface compounds, it is called chemical adsorption

Discussion

504.	What is desorption?
Answer» The process of remove of adsorbed substance is called desorption. The process of remove of adsorbed substance is called desorption.

Discussion

505.	Occlusion is the absorption of aA. gas into the bulk of a solidB. gas into the bulk of a liquidC. liquid into the bulk of a solidD. liquid into the bulk of a liquid
Answer» Correct Answer - A The term "Occlusion" was proposed by `T` . Graham in connection with his studies on the taking up of hydrogen gas by palladium.

Discussion

506.	What is occlusion?
Answer» The adsorption of gases on the surface of metals is called occlusion. The adsorption of gases on the surface of metals is called occlusion.

Discussion

507.	What type of interaction occuring between gas molecules and a solid surface is responsible for chemisorption of a gas on solid.
Answer» Chemical bonds occur between gas molecules and a solid surface, is responsible for chemisorption of the gas on solid.

Discussion

508.	Micelles have :A. higher colligative properties as compared to common colloidal solsB. lower colligative propertiesC. same colligative propertiesD. none in true
Answer» Correct Answer - B

Discussion

509.	Which of the following ions has maximum flocculation value?A. `Cl^(-)`B. `SO_(4)^(-2)`C. `PO_(4)^(3-)`D. `[Fe(CN)_(6)]^(4-)`
Answer» Correct Answer - D

Discussion

510.	Which of the following Sol is formed due to following Rxn :- `SnO_(2)+HCl` (Excess) :-A. `[SnCl_(4)]Cl^(-)`B. `[SnCl_(4)]O^(-2)`C. `[SnCl_(4)]H^(+)`D. None
Answer» Correct Answer - A

Discussion

511.	Which one of the following is correctly matched?A. Emulsion-CurdB. Foam-MistC. Aerosol-SmokeD. Solid sol-Cake.
Answer» Correct Answer - C Smoke is an aerosol ( solid carbon particles dispersed in air)

Discussion

512.	Fog is colloidal solution of:-A. Liquid is gasB. Gas in liquidC. Solid in gasD. Gas in gas
Answer» Correct Answer - A Fog is a colloidal solution of liquid in gas.

Discussion

513.	Which forms cationic micelle ?A. Sodium dodecyl sulphateB. Sodium acetateC. UreaD. Cetyl trimethyl ammonium bromide
Answer» Correct Answer - D Sodium dodecyl sulphate forms anionic micelles due to aggregation of anion whereas ` CTAB` forms cationic micele due to aggregation of cation .

Discussion

514.	Which type of metals form effecive catalyssts ?A. Alkali metlaB. Transiton metalsC. Alkaline earthsD. Radioactive metals
Answer» Correct Answer - B Transition metals are more are more effective catalyst on accoun of their larger surfae area and half-filled nature of penultimate d-subshells .

Discussion

515.	Which is wrong in case of enzyme catalysis ?A. Enzymes are in collodal state at an optimum temperatureB. Enzymes work at an optimum ` pH`C. Enzymes are highly specific for substratesD. An enzyme raises activatio enrgy
Answer» Correct Answer - D First three are characteristic of enzyme catalysed reactions.

Discussion

516.	The decomposition of hydrogen peroxide can be slowed by the addition of a small amount of acetamide. The latter acts as aA. InhibitorB. PromoterC. ModeratorD. Posion
Answer» Correct Answer - A

Discussion

517.	The decomposition of hydrogen peroxide can be slowed by addition of a small amount of acetamide .A. Detainer B. stopperC. PromoterD. Inhibitor
Answer» Correct Answer - D Inhibitors are also catalysts but that slow down the rate of reaction.

Discussion

518.	The decomposition of hydrogen peroxide can be slowed by addition of a small amount of acetamide .A. detainerB. stopperC. promoterD. inhibitor
Answer» Correct Answer - D Acetamide acts as negative catalyst for decompositon of ` H_2 O_2` .

Discussion

519.	Which one is false in the following statement?A. A catalyst is specific in its actionB. A very small amount of the catalyst alters the rate of reaction.C. The number of free vacancies on the surface of a catalyst increase on sub-division.D. `Ni` is used as a catalyst in the manufacture of ammonia.
Answer» Correct Answer - D Finely divided iron is used as catalyst in manufacture of `NH_(3)`.

Discussion

520.	`As_(2)S_(3)` has a negative charge. Capacity to precipate it is highest inA. `AlCl_(3)`B. `Na_(3)PO_(4)`C. `CaCl_(2)`D. `K_(2)SO_(4)`
Answer» Correct Answer - A Negatively charged `As_(2)S_(3)` sol coaulated most effectively by `AlCl_(3)`. This is because oppositely charged `Al^(+++)` ions have maximum charge. `As^(3+) gt Ca^(2+) gt Na^(+)`.

Discussion

521.	Noble gases are adsorbed byA. Anhydrous calcium chlorideB. Farric hydroxideC. Cons, `H_(2)SO_(4)`D. Activated cocount charcoal
Answer» Correct Answer - D Noble gases are adsorbed by coconut charcoal. The adsorption of different noble gases occure at different temperature. Hence charcoaol is used to separated these gases. Helium is not adsorbed by charcoal (as it is very difficult for liquefiable gas).

Discussion

522.	A catalyst increase rate of reaction by :A. Decreasing enthalpyB. Decreasing internal energyC. Decreased activation energyD. Increase activation energy
Answer» Correct Answer - C Catalyst provides new path to the chemical reaction which has lower value of activation energy. Reactant and product with not be affected, so there will not be any change in state parameter like enthalpy and internal energy.

Discussion

523.	According to the adsorption theory of catalysis, the speed of the reaction increases becauseA. Adsorption lowers the activation energy of the reactionB. The concentration of reactant molecules at the active centres of the catalyst becomes high due to adsorptionC. In the process of adsorption, the activation energy of the molecules becomes largeD. Adsorption produces heat which increases the speed of the reaction.
Answer» Correct Answer - A

Discussion

524.	Which of the following acts as a negative catalysts ?A. Tetraethyl Lead as antiknock compoundB. Glycerol in decomposition of `H_(2)O_(2)`C. Ethanol in the oxidation of chloroformD. All the above
Answer» Correct Answer - D

Discussion

525.	the process whichh is catalysed by one of the product is calledA. Acid-base catalysisB. AutocatalysisC. Negative catalysisD. None of these
Answer» Correct Answer - B

Discussion

526.	Among the following the surfactant that will from micelles in squeous solution at the lowest molar concentration at ambident condition is :A. `CH_(3)(CH_(2))_(15)N^(+)(CH_(3))_(3)Br`B. `C H_(3)(CH_(2))_(11)OSO_(3)^(-)Na^(+)`C. `CH_(3)(CH_(2))_(6)CO O^(-)Na^(+)`D. `CH_(3)(CH_(2))_(11)N^(+)(CH_(3))_(3)Br`
Answer» Correct Answer - B In case of detergents, e.g., sodium lauryl sulphate viz. `CH_(3)(CH_(2))_(11)SO_(4)^(-)Na^(+),` the polar group is `R-OSO_(3)^(-)` along with the long hydrocarbon chain will for micelle.

Discussion

527.	Write the balanced reaction of titration of `KMnO_(4)` Vs oxalic acid in presence of `H_(2)SO_(4)`.A. `H_(2)SO_(4)`B. `KMnSO_(4)`C. Oxalic acidD. `MnSO_(4)`
Answer» Correct Answer - D `MnSO_(4)` acts as autocatalyst during the titration of `KMnO_(4)` and oxalic acid in presence of `H_(2)SO_(4).MnSO_(4)` is formed during the reaction. `5H_(2)C_(2)O_(4)+2KMnO_(4)+3H_(2)SO_(4)`

Discussion

528.	Whenever a mixture of gases is allowed to come in contact with a particular adsorbent under the same conditions, the more strong adsorbate is adsorbed to greater extent irrespective of its amount present, e.g., `H_(2)O` is adsorbed to more extent on silica gel than `N_(2)` and `O_(2)`. This shows that some adsorbates are preferentially adsorbed. It is also observed that preferentially adsorbable adsorbent can displace a weakly adsorbed substance from the surface of an adsorbent. Preferential adsorption depends on strength of attraction, surface area, polar nature and other factors.A. HClB. `N_(2)`C. `CH_(4)`D. `H_(2)`
Answer» Correct Answer - A

Discussion

529.	Whenever a mixture of gases is allowed to come in contact with a particular adsorbent under the same conditions, the more strong adsorbate is adsorbed to greater extent irrespective of its amount present, e.g., `H_(2)O` is adsorbed to more extent on silica gel than `N_(2)` and `O_(2)`. This shows that some adsorbates are preferentially adsorbed. It is also observed that preferentially adsorbable adsorbent can displace a weakly adsorbed substance from the surface of an adsorbent. Preferential adsorption depends on strength of attraction, surface area, polar nature and other factors. Which of the following isomer of `C_(6)H_(14)` is adsorbed to maximum extent?A. Normal hexaneB. Neo-hexaneC. Iso-hexaneD. 3-Methyl pentane
Answer» Correct Answer - A

Discussion

530.	Assertion(A): Catalysts are aways transition metals. Reason(R): Trasition metals have varitable oxidation state.A. If both (A) and (R) are correct, and (R) is not the correct explanation of (A)B. If both (A) and (R) are correct, but (R) is the correct explanation of (A).C. If (A) is correct, but (R) is incorrect.D. If (A) is incorrect, but (R) is correct. S
Answer» Correct Answer - B

Discussion

531.	Assertion(A): Fruit formation process shows increase in the rate with passage of time. Reason(R): Hydrolysis os these ester is homogeneous autocatalytic reaction.A. If both (A) and (R) are correct, and (R) is the correct explanation of (A)B. If both (A) and (R) are correct, but (R) is the correct explanation of (A).C. If (A) is correct, but (R) is incorrect.D. If (A) is incorrect, but (R) is correct. S
Answer» Correct Answer - A

Discussion

532.	Assertion(A): A catalyst speed up a reaction but does not participate in its mechanism. Reason(R): A catalyst provides an alternative path of lower activation energy to the reactants.A. If both (A) and (R) are correct, and (R) is the correct explanation of (A)B. If both (A) and (R) are correct, but (R) is the correct explanation of (A).C. If (A) is correct, but (R) is incorrect.D. If (A) is incorrect, but (R) is correct. S
Answer» Catalyst may decreases the speed of reaction.

Discussion

533.	What is the role of diffusion in heterogeneous catalyst?
Answer» Diffusion of gas molecules occur at the surface of catalyst (solid) followed by adsorption. In the same way, the product formed diffuse from the surface of the catalyst leaving the surface free for more reactant molecules to get adsorbed and undergo reaction.

Discussion

534.	How is dialysis carried out? Mention its one application.
Answer» Dialysis is used for purification of colloidal solution. It is carried out by putting impure colloidal solution in a parchment paper bag and then dipping it in distilled water. After some times, the molecules and ions diffuse through the membrane into the water leaving the pure colloidal solution behind. An important application of dialysis is during the purification of blood in the artificial kideny machin. Dialysis is used for purification of colloidal solution. It is carried out by putting impure colloidal solution in a parchment paper bag and then dipping it in distilled water. After some times, the molecules and ions diffuse through the membrane into the water leaving the pure colloidal solution behind. An important application of dialysis is during the purification of blood in the artificial kideny machin.

Discussion

535.	Detergents often containA. RCOONaB. RONaC. RSNaD. `ROSO_(2)Na`
Answer» Correct Answer - A Commercial detergents mainly contain salts of higher fatty acids.

Discussion

536.	Coagulation value isA. Minimum concentration of electrolyte required to cause coagulationB. Expressed in millimoles per litreC. Expressed in milligramD. Also known as flocculation value
Answer» Correct Answer - A::B::D

Discussion

537.	A dispersion of `AgCl` in water isA. Hydrophilic colloidB. An emulsionC. an alcosolD. hydrophobic sol
Answer» Correct Answer - B Lyophobic sols include sols, of metals and their insoluble compounds like sulphides, chloride and oxides. They need stabilizing substances for preservation, dispersion medium is water.

Discussion

538.	Which is an example of coagulation?A. Curdling of milkB. Purification of water by addition of alumC. Formation of deltas at the river bedsD. All the three are examples of coagulation
Answer» Correct Answer - D

Discussion

539.	Which one of the following is not a property of hydrophilic solsA. High concentrations of dispersed phase can be easily attainedB. Coagulation is reversibleC. Viscosity and surface tension are about the same as for waterD. The charge of the particle depends on the pH values of the medium, it may be positive, negative or even zero
Answer» Correct Answer - C Viscosity and surface tension are not same for water in hydrophilic sols.

Discussion

540.	Soaking of water by a sponge is an example of :A. Simple adsorptionB. Physical adsorptionC. ChemisoptionD. Absorption
Answer» Correct Answer - D

Discussion

541.	Which of the following anions will have minimum flocculation value for the ferric oxide solution?A. `Cl^(-)`B. `Br^(-)`C. `SO_(4)^(2-)`D. `[Fe(CN)_(6)I^(3-)`
Answer» Correct Answer - B

Discussion

542.	Which of the following anions will have minimum flocculation value for the ferric oxide solution?A. `NaCl`B. `Na_(2)S`C. `(NH_(4))_(3)PO_(4)`D. `K_(2)SO_(4)`
Answer» Correct Answer - A Flocculation value `prop(1)/("Coagulating power")` Greater the coagulating power of effective ion, lower will be the flocculation value of the electrolyte. `Fe(OH)_(3)` is a positively charged sol. According to Hardy schulze, rule, greater the charge on the oppositely charged ion of the electrolyte added, more effective it is in bringing coagulation. Among the four electrolytes, NaCl has the lowest coagulating power, so its flocculation value will be maximum.

Discussion

543.	Which of the followig characteristics is not correct for physical adsorption ?A. Adsorption increases with increase in temperatureB. Adsorption is spontaneousC. Both enthalpy and entropy of adsorption are negativeD. d
Answer» Correct Answer - A Adsorption decreases with increase in temperature since it is of exothemic nature.

Discussion

544.	which on e of the following characteristics is correct for physical adsorption ?A. it is very specificB. Adsorption on solids is irreversibleC. Adsorption decreases with decrease in temperatureD. Generally both enthaply and entropy of adsorption are negative
Answer» Correct Answer - d

Discussion

545.	Example of an intrinsic colloid isA. GlueB. SulpharC. `Fe`D. `As_(2)H_(3)`
Answer» Correct Answer - A On shaking with the dispersion nedium, colloidal directly form the colloidal sol. Hence they are called intrinsic colloids. i.e, glue.

Discussion

546.	Example of an intrinsic colloid isA. `As_(2)S_(3)` solB. S solC. Egg albuminD. `Fe(OH)_(3)` sol
Answer» Correct Answer - CCorrect Answer - C

Discussion

547.	which of the following colloidal systems, fog is an example?A. Liquid dispersed in gasB. Gas dispersed in GasC. Solid dispersed in gasD. Solid dispersed in liquid
Answer» Correct Answer - A In fog, liquid water is dispersed in gas. Correct Answer - A In fog, liquid water is dispersed in gas.

Discussion

548.	Which one of the following statements is wrong about adsorption?A. It is a selective and specific process.B. It is a reversible process.C. An increase in the gaseous adsorbate causes an increases in a adsorption. However, at high pressure, the adsorption becomes constant.D. It is an endothrmic process.
Answer» Correct Answer - D Adsorption is an exothermic process.

Discussion

549.	Soaking of water by a sponge is an example of :A. simple adsorptionB. physical adsorptionC. chemisorptionD. absorption
Answer» Correct Answer - D Sponge absorbs water .

Discussion

550.	Which of the following are incorrect statements ?A. Hardy schulz rule is related to coagulationB. Brownian movement and Tyndall effect are the characteristic of colloids.C. In gel, the liquid is dispersed in liquidD. Higher the gold number, more is the protective power of lyophillic sols.
Answer» Correct Answer - C::D

Discussion

Explore topic-wise InterviewSolutions in .

Freundlich isotherm explains the behaviour of adsorptionA. CorrectlyB. ApproximatelyC. WronglyD. At very high temperature only

What is meant by chemical adsorption?

What is desorption?

Occlusion is the absorption of aA. gas into the bulk of a solidB. gas into the bulk of a liquidC. liquid into the bulk of a solidD. liquid into the bulk of a liquid

What is occlusion?

What type of interaction occuring between gas molecules and a solid surface is responsible for chemisorption of a gas on solid.

Micelles have :A. higher colligative properties as compared to common colloidal solsB. lower colligative propertiesC. same colligative propertiesD. none in true

Which of the following ions has maximum flocculation value?A. `Cl^(-)`B. `SO_(4)^(-2)`C. `PO_(4)^(3-)`D. `[Fe(CN)_(6)]^(4-)`

Which of the following Sol is formed due to following Rxn :- `SnO_(2)+HCl` (Excess) :-A. `[SnCl_(4)]Cl^(-)`B. `[SnCl_(4)]O^(-2)`C. `[SnCl_(4)]H^(+)`D. None

Which one of the following is correctly matched?A. Emulsion-CurdB. Foam-MistC. Aerosol-SmokeD. Solid sol-Cake.

Fog is colloidal solution of:-A. Liquid is gasB. Gas in liquidC. Solid in gasD. Gas in gas

Which forms cationic micelle ?A. Sodium dodecyl sulphateB. Sodium acetateC. UreaD. Cetyl trimethyl ammonium bromide

Which type of metals form effecive catalyssts ?A. Alkali metlaB. Transiton metalsC. Alkaline earthsD. Radioactive metals

Which is wrong in case of enzyme catalysis ?A. Enzymes are in collodal state at an optimum temperatureB. Enzymes work at an optimum ` pH`C. Enzymes are highly specific for substratesD. An enzyme raises activatio enrgy

The decomposition of hydrogen peroxide can be slowed by the addition of a small amount of acetamide. The latter acts as aA. InhibitorB. PromoterC. ModeratorD. Posion

The decomposition of hydrogen peroxide can be slowed by addition of a small amount of acetamide .A. Detainer B. stopperC. PromoterD. Inhibitor

The decomposition of hydrogen peroxide can be slowed by addition of a small amount of acetamide .A. detainerB. stopperC. promoterD. inhibitor

Which one is false in the following statement?A. A catalyst is specific in its actionB. A very small amount of the catalyst alters the rate of reaction.C. The number of free vacancies on the surface of a catalyst increase on sub-division.D. `Ni` is used as a catalyst in the manufacture of ammonia.

`As_(2)S_(3)` has a negative charge. Capacity to precipate it is highest inA. `AlCl_(3)`B. `Na_(3)PO_(4)`C. `CaCl_(2)`D. `K_(2)SO_(4)`

Noble gases are adsorbed byA. Anhydrous calcium chlorideB. Farric hydroxideC. Cons, `H_(2)SO_(4)`D. Activated cocount charcoal

A catalyst increase rate of reaction by :A. Decreasing enthalpyB. Decreasing internal energyC. Decreased activation energyD. Increase activation energy

Which of the following acts as a negative catalysts ?A. Tetraethyl Lead as antiknock compoundB. Glycerol in decomposition of `H_(2)O_(2)`C. Ethanol in the oxidation of chloroformD. All the above

the process whichh is catalysed by one of the product is calledA. Acid-base catalysisB. AutocatalysisC. Negative catalysisD. None of these

Write the balanced reaction of titration of `KMnO_(4)` Vs oxalic acid in presence of `H_(2)SO_(4)`.A. `H_(2)SO_(4)`B. `KMnSO_(4)`C. Oxalic acidD. `MnSO_(4)`

What is the role of diffusion in heterogeneous catalyst?

How is dialysis carried out? Mention its one application.

Detergents often containA. RCOONaB. RONaC. RSNaD. `ROSO_(2)Na`

Coagulation value isA. Minimum concentration of electrolyte required to cause coagulationB. Expressed in millimoles per litreC. Expressed in milligramD. Also known as flocculation value

A dispersion of `AgCl` in water isA. Hydrophilic colloidB. An emulsionC. an alcosolD. hydrophobic sol

Which is an example of coagulation?A. Curdling of milkB. Purification of water by addition of alumC. Formation of deltas at the river bedsD. All the three are examples of coagulation

Soaking of water by a sponge is an example of :A. Simple adsorptionB. Physical adsorptionC. ChemisoptionD. Absorption

Which of the following anions will have minimum flocculation value for the ferric oxide solution?A. `Cl^(-)`B. `Br^(-)`C. `SO_(4)^(2-)`D. `[Fe(CN)_(6)I^(3-)`

Which of the following anions will have minimum flocculation value for the ferric oxide solution?A. `NaCl`B. `Na_(2)S`C. `(NH_(4))_(3)PO_(4)`D. `K_(2)SO_(4)`

Which of the followig characteristics is not correct for physical adsorption ?A. Adsorption increases with increase in temperatureB. Adsorption is spontaneousC. Both enthalpy and entropy of adsorption are negativeD. d

which on e of the following characteristics is correct for physical adsorption ?A. it is very specificB. Adsorption on solids is irreversibleC. Adsorption decreases with decrease in temperatureD. Generally both enthaply and entropy of adsorption are negative

Example of an intrinsic colloid isA. GlueB. SulpharC. `Fe`D. `As_(2)H_(3)`

Example of an intrinsic colloid isA. `As_(2)S_(3)` solB. S solC. Egg albuminD. `Fe(OH)_(3)` sol

which of the following colloidal systems, fog is an example?A. Liquid dispersed in gasB. Gas dispersed in GasC. Solid dispersed in gasD. Solid dispersed in liquid

Soaking of water by a sponge is an example of :A. simple adsorptionB. physical adsorptionC. chemisorptionD. absorption

Which of the following are incorrect statements ?A. Hardy schulz rule is related to coagulationB. Brownian movement and Tyndall effect are the characteristic of colloids.C. In gel, the liquid is dispersed in liquidD. Higher the gold number, more is the protective power of lyophillic sols.