InterviewSolution
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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The blue colour of the sky is duo toA. scattering of light due to the ozone layerB. scattering of light from the sunC. scattering of light from particles of dust in the atmosphereD. all of these |
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Answer» Correct Answer - C Although all gases and liquids scatter light, the scattering from a pure substance or ture solution is quite small and usually or not detectable. However, because of the considerable depth of the atmosphere, the scattering of light by air molecules can be seen. The blue colour of the sky is due to the fact that blue light is scattered more easily than red or any other light. |
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| 2. |
How do micelles differ from a normal colloidal solutions ? |
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Answer» Some substances which at low concentrations behave as normal strong electrolytes, but at high concentrations exhibit colloidal behaviour due to formation of ag gregates. The aggregate particles thus formed are called micelles. `to` These are also known as associated colloids. `to` These colloids have both lyophilic and lyophobic parts. `to` Micelles may contain as many as 100 or more of normal molecules. `to` On dilution these colloids revert back to individual electrolytes. |
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| 3. |
Peptization is a process of :A. precipitation of colloidal particlesB. purification of colloidsC. dispersing precipitate into colloidal solsD. movement of colloidal particles in the electrical field |
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Answer» Correct Answer - C |
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| 4. |
peptization involves :A. precipitation of colloidal particlesB. disintegration of colloidal aggregatesC. purifiction of colloidsD. impact of molecules of the dispersion medium on the colloidal particles |
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Answer» Correct Answer - b |
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| 5. |
Peptization is a process of :A. precipitating colloidal particlesB. purifying colloidal particlesC. dispersing the precitiate into colloidal stateD. none of these |
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Answer» Correct Answer - C The phenomenon of converting freshly precititated mass into colloidal state by the action fo solutie or solvent is called peptization . |
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| 6. |
Substances that form aggerated particles (micelles) at higher concentration are known asA. associated colloidsB. lyophilic colloidsC. multimolecular colloidsD. lyophobic colloids |
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Answer» Correct Answer - A These colloids have both `1` Iyophobic as well as lyophic parts. |
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| 7. |
What is Peptization ? |
| Answer» Peptization : The process of converting a precipitate into colloidal sol by shaking it with the dispersion medium in the presence of a small amount of electrolyte is called Peptization. | |
| 8. |
What is meant by the term peptization? |
| Answer» The process of conversion of a freshly prepared precipitate into a colloidal solution by adding a suitable electrolyte is called peptization. The process of conversion of a freshly prepared precipitate into a colloidal solution by adding a suitable electrolyte is called peptization. | |
| 9. |
What are miclells? How do they differ from ordianry cordinary colloidal particles? Give two examples of micelles-forming substances. |
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Answer» There are some substance which at low concentration behave as normal electrolyte but at higher concentrations exhibit colloidal behaviour due to the formation of aggergated particles. The aggerated particles thus formation of aggerated particles. The aggregated particles thus formed are called micelles. The formation of micelles takes place only above a particular temperature called Kraft temperature and above a particular concentration (CMC). On dilution these colloids revert back to individual inos. Examples are soaps and sytheric detergents. There are some substance which at low concentration behave as normal electrolyte but at higher concentrations exhibit colloidal behaviour due to the formation of aggergated particles. The aggerated particles thus formation of aggerated particles. The aggregated particles thus formed are called micelles. The formation of micelles takes place only above a particular temperature called Kraft temperature and above a particular concentration (CMC). On dilution these colloids revert back to individual inos. Examples are soaps and sytheric detergents. |
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| 10. |
State Hardy schulze rule. |
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Answer» Greater the valency of the action ion of the electrolyste, greater will be its precipitating action. `Al^(3+)gtMg^(2+)Na^(o+)` for negatively charged sols `PO_(4)^(3-)gtCl^(ɵ)` for positively charged sols Greater the valency of the action ion of the electrolyste, greater will be its precipitating action. `Al^(3+)gtMg^(2+)Na^(o+)` for negatively charged sols `PO_(4)^(3-)gtCl^(ɵ)` for positively charged sols |
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| 11. |
What is Kraft tempreature? |
| Answer» Kraft temperature is the minimum temperature above which the formation of miscelles takes place. Kraft temperature is the minimum temperature above which the formation of miscelles takes place. | |
| 12. |
MULTIMOLECULAR COLLOIDS, MACROMOLECULAR AND ASSOCIATED COLLOIDS |
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Answer» a. Multimolercular cooloids: A large number of atoms or smaller molecules of a substance on dissolution aggregate together to form species having size (diameter lt1mm) in the colloidal range `(1-1000nm)` . Such species are, known as multimolecular colloids. For example, a sulphur sol consist of particles containing a thousand or more `S_(S)` sulphur molecules. b. Macromolecular colloids: Macromolecules (starch, cellulose, proteins and nylon, polyethene, etc.) when dissolved in suitable solvent form a solution wherein the size of the macromolecules may fall within the colloidal range. Such systems are called macromolecular colloids.a. Multimolercular cooloids: A large number of atoms or smaller molecules of a substance on dissolution aggregate together to form species having size (diameter lt1mm) in the colloidal range `(1-1000nm)` . Such species are, known as multimolecular colloids. For example, a sulphur sol consist of particles containing a thousand or more `S_(S)` sulphur molecules. b. Macromolecular colloids: Macromolecules (starch, cellulose, proteins and nylon, polyethene, etc.) when dissolved in suitable solvent form a solution wherein the size of the macromolecules may fall within the colloidal range. Such systems are called macromolecular colloids. |
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| 13. |
The fresh precipitate can be transformed in colloidal state byA. peptizationB. coagulationC. diffusionD. None of these |
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Answer» Correct Answer - A The dispersion of a freshly precipitated material into colloidal solution by the action of a suitable electrolyte is termed peptization. The electrolyte used for this purpose is called a peptizing agent. |
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| 14. |
Give two examples of associated colloids. |
| Answer» Surface active agents such as soaps and synthetic detergents are examples of associated colloids. | |
| 15. |
Assertion: The conversion of fresh precipitate to colloidal state is called peptization. Reason: It is caused by addition of common ions.A. if both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true but reason is not the correct explanation of the assertionC. If assertion is true but reason is false.D. If the assertion and reason both are false. |
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Answer» Correct Answer - B Correct reason to assertion is that common ion absorb on the surface of precipitate. Due to repulsion between adsorbed ions, the precipitate undergo fragmentaion resulting in colloidal state. |
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| 16. |
Statements : The separation of insoluble impurities form a colloidal solution requires dialysis . Expabnations : The ionic impurites present in collidal solution are separated by electrodialysis .A. S is correct but E is wrong .B. S is worong but E is correctC. Both S and E are correct and E is correct explanation of (S) .D. Both S and E are correct but E is not correct explanation of S. |
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Answer» Correct Answer - B Soluble impouites are removed by dialysis . |
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| 17. |
Assertion :- Associated colloids are formed by aggregation of large no. of ions in `conc^(n)` solution of Soap. Reason :- Because associated colloids have more than one colloidal particles.A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.B. If both Assertion & Reason are True but Reason is not a correct explanation of the Assertion.C. If Assertion is True but the Reason is False.D. If both Assertion & Reason are False. |
| Answer» Correct Answer - B | |
| 18. |
The coagulation of the lyophobic sols can be carried out byA. electrophoresisB. persistent dialysisC. addition of electrolytesD. all of these |
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Answer» Correct Answer - D The stablity of the lyophobic sols is due to the presence of charge is removed, the particles will come nearer to each other to form aggregates (or coagulate) and settle down under the force of gravity. During elecrophoresis,the colloidal particles move towards oppositely charged electrodes,get discharged and precipitated.On prolonged dialysis, traces of the elecrolyte present in the sol (needed for their stabilization) are removed almost completely and the colloids become unstable and ultimately coagulate. When excess of an elecrolyte is added,the colloidal particles are precipitated.The reason is that colloids interact with ions carrying charge opposite to that present on themselves.This causes neutralization leading to thier coagulation.The ion responsible for neutralization of charge on the particles is called the coagulating ion. A negative ion causes the precipitation of positively charged sol and vice versa. We can also coagulate lyphobic sols by mixing two oppositely charged sols and by boiling.When mixed in almost equal proportions,oppositely charged sols neutralize their charges and get partially or completely precipitated.For example,mixing of hydrated ferric oxide (+ve sol) and arsenious sulphide (-ve sol) bring them in the precipitated forms.This type of coagulation is called mutual coagulation. When a sol os boiled,the adsorbed layer is disturbed due to increased collisions with the particles of dispersion medium. This reduces the charge on the particles and ultimately lead to settling down in the form of a precipitate. |
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| 19. |
Process of aggregation of colloidal particles into an insoluble precipitate by the addition of some suitable electrolye is known asA. coagulationsB. flocculationC. peptizationD. precipitation |
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Answer» Correct Answer - A The presence of small amount of appropriate electrolytes is necessary for the stablility of the colloids. How-ever,when an electrolytic is added in larger concentration,the particles of the take up the ions which which are oppositely charged and thus get neutralized.The neutral particles then start aggregating giving particles of larger size which are then precipitated. The process of settling of colloidal particles is called coagulation (or precipitation) of the sol. At lower concentration of electrolytes,the aggregation of particles is called flocculation that can be reversed on shaking while at higher concentration of elecrolyte,coagulation takes place and the same cannot be reversed simply by shaking. When river water containing colloidal clay flows into sea,elecrolytes present in the brine induce aggregation. This is a major cause of silting in estuaries. |
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| 20. |
Which of the following is/are not possible in case of autocatalysis?A. Reactant catalysisB. Heat produced in the reaction catalysisC. Product catalysisD. Solvent catalysis |
| Answer» Correct Answer - A::B::DCorrect Answer - A::B::D | |
| 21. |
Which of the following statement is incorrect ?A. A catalyst initiates a chemical reactionB. A catalyst remains unchanged in concentration at the end of a reactonC. A catalyst does not alter the equilibrium in a reversible reactionD. A catalyst is generally specific in a reaction |
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Answer» Correct Answer - A A catalst never initial a chemical reaction because is does not change `DeltaG` of the reaction. Catalyst accelerates the attainment of equilibrium but does not shift its position. |
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| 22. |
An example of micelle isA. Sodium stearateB. Sodium lauryl sulphateC. Sodium alkyl benzene sulphonateD. Sodium benzoate |
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Answer» Correct Answer - A::B::C (a),(b),(c) can form accociated colloids i.e., micelle whereas (d) sodium benzoate cannot form micelle. |
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| 23. |
Which of the following statement/s is/are not correctA. Physical adsorption is directly related to the critical temperature of the gas (adsorbate)B. One gram of charcoal at `25^(@)C` will always adsorb the same amount of a particular gas at a particular pressureC. At particular temperature, adsorption always increases with increase of pressureD. In adsorption, the concentration of adsorbate is always greater at the surface of the adsorbent |
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Answer» Correct Answer - B::C::D (b) is wrong because adsorption depends upon the surface area. (c) is wrong because at about `0^(@)C`, adsorption remains constant after a particular pressure. (d) Is wrong because there can be negative adsorption also. |
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| 24. |
In a reversible reaction, a catalystA. affects only the reverse reactionB. affects only the forward reactionC. affects both the forward and reverse reactions to the same extentD. increases the rate of forward but deceases the rate of backward reaction. |
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Answer» Correct Answer - C Both inorganic and boichemical catalysts accelerate the forward as well as reverse reaction by precisely the same factor. |
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| 25. |
An exammple of autocatalysis isA. Oxidation of NO to `NO_(2)`B. Oxidation of `SO_(2)` to `SO_(3)`C. Decomposition of `KClO_(3)` to `KCl` and `O_(2)`D. Oxidation of oxalic acid by acidified `KMnO_(4)` |
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Answer» Correct Answer - D `2KMnO_(4)+5H_(2)C_(2)O_(4)+3H_(2)SO_(4)toK_(2)SO_(4)+2KMnSO_(4)+8H_(2)O+10CO_(2)` the pink colour of `KMnO_(4)` disappears slowly on treating it with oxalic acid, but the rate of disappearance of colour fastens after sometime due to the formation fo `Mn^(2+)` ions which acts as autocatalyst for the reaction. |
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| 26. |
Which of the following is an example of an autocatalytic reaction ?A. Hydrogenation of vegetable oil using Ni CatalystB. Breakdown of `._(6)^(14)C`C. Thermal decomposition of a mixture `KClO_(3)` and `MnO_(2)` .D. Decomposition of nitroglycerine |
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Answer» Correct Answer - D When one of the products of a reaction may act as a catalyst for the reaction, the phenomenon is known as auto catalysis `N_(2)` one of products of decomposition of nitroglycerine, plays the role of an auto catalyst. |
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| 27. |
In a Homogenous catalysis:-A. the catalyst and the reactants should be gasesB. The catalyst and the reactants should form a single phaseC. Catalyst and the reactants are all solidsD. The catalyst and the reactions are all liquids. |
| Answer» Correct Answer - B | |
| 28. |
Lyophilic sols are also called reversible colloids becauseA. they can be reformed by mixing residue (dispersed phase) in dispersion medium even after dryingB. they can be easily precipitated from the colloidal systemC. once formed, the disperison medium and dispersed phase cannot be separaedD. special reversible reactions are used to prepare them. |
| Answer» Correct Answer - A | |
| 29. |
An exammple of autocatalytic reaction is:-A. The decomposition of nitroglycerineB. Thermal decomposition of `KClO_(3)` and `MnO_(2)` mixtureC. Break down of `._(6)C^(14)`D. Hydrogenation of vegetable oil using nickel catalyst |
| Answer» Correct Answer - A | |
| 30. |
Which one of the following statements is correct in reversible reaction A catalystA. Increases the rate of forward reactionB. Decreases the rate of forward reactionC. Increases thhe rate of backward and forward reactionD. Alters the equilibrium constant of the reaction |
| Answer» Correct Answer - C | |
| 31. |
A catalyst can affect reversible reaction by:-A. Changing equilibriumB. Slowing forward reactionC. Attaining equilibrium in both directionD. None of these |
| Answer» Correct Answer - C | |
| 32. |
mark the correct statement in a reversible reaction:-A. The catalyst catalysis the forward reactionB. The catalyst catalysis the backward reactionC. The catalyst influences the direct and the reverse reaction to the same extentD. The catalyst increases the rate of forward reaction and decreases the rate of backward reaction. |
| Answer» Correct Answer - C | |
| 33. |
In the titration between oxalic acid ad acidified potassium permanganate, the manganous salt formed catalyses the reaction. The manganous salt is:-A. A promoterB. A positive catalystC. An autocatalystD. None of these |
| Answer» Correct Answer - C | |
| 34. |
A catalyst remains unchanged at the end of the reaction regardingA. MassB. Pysical stateC. Physical state and chemical compositionD. Mass and chemical composition |
| Answer» Correct Answer - D | |
| 35. |
The amount of gas adsorbed physically on charcoal increases with :A. temperature and pressureB. tempreature and decrease with pressureC. pressurea and decrease with temperatureD. none of these |
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Answer» Correct Answer - C Adsorption of gases increases with pressure , decrease with temperature . |
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| 36. |
The colloidal solution of two immiscible liquids in which one of the liquids acts as a dispersed phase and the other as dispersion medium is called emulsion. Milk is an example of emulsion in which fat globules are dispersed in water. Emuldion are of two types i.e., O/W and W/O type emulsion, identified by dilution test, conductivity test and dye test. In milk, whihc acts as an emulsifier ?A. GelatinB. AlbuminC. CaseinD. none of these. |
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Answer» Correct Answer - C Casein (protein) acts as an emulsifier. |
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| 37. |
Depending upon whether the dispersed phase and the dispersion medium are solids, liquids or gases _______ types of colloidal systems are possible.A. threeB. sixC. eightD. nine |
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Answer» Correct Answer - C Solid dispersed phase can be mixed solid liquid or ges disperision medium i.e. two condinations are possible However gas dispersed phased can be mixed with solid or liquid dispersion medium i.e. two are possible a gas mixture with another gas always forms a homogeneous mixture and hence is not a colloidal system. |
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| 38. |
Emulsions are also called the colloidal solutions in which the disperse phase as well as dispersion medium are liquids. It may be oil-in-water or water-inoil type Emulsifiers can be sued to stabilize the emulsion. Soaps, detergents, proteins, and gums are used as emulsifiers. Which of the following examples is/are oil-in-water-type emulsion?A. InkB. DetergentC. SoapD. Milk |
| Answer» Correct Answer - DCorrect Answer - D | |
| 39. |
The colloidal solution of two immiscible liquids in which one of the liquids acts as a dispersed phase and the other as dispersion medium is called emulsion. Milk is an example of emulsion in which fat globules are dispersed in water. Emuldion are of two types i.e., O/W and W/O type emulsion, identified by dilution test, conductivity test and dye test. Which property is observed in an emulsion ?A. Tyndall effectB. Brownian motionC. Both a and bD. none of these. |
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Answer» Correct Answer - C Emulsions exhibit both tyndal effect and Brownian movement. |
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| 40. |
Emulsions are also called the colloidal solutions in which the disperse phase as well as dispersion medium are liquids. It may be oil-in-water or water-inoil type Emulsifiers can be sued to stabilize the emulsion. Soaps, detergents, proteins, and gums are used as emulsifiers. Emulsion can be destroyed by (more than one correct)A. The addition of emulsifier which tends to form another emulsionB. Electrophorsis with high potentialC. FreezingD. All |
| Answer» Correct Answer - B::CCorrect Answer - B::C | |
| 41. |
The colloidal solution of two immiscible liquids in which one of the liquids acts as a dispersed phase and the other as dispersion medium is called emulsion. Milk is an example of emulsion in which fat globules are dispersed in water. Emuldion are of two types i.e., O/W and W/O type emulsion, identified by dilution test, conductivity test and dye test. Choose the correct answer:A. O/WB. W/OC. Both a and bD. none of these. |
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Answer» Correct Answer - A Oil in water type emulsions are conducting in nature. |
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| 42. |
Emulsions are also called the colloidal solutions in which the disperse phase as well as dispersion medium are liquids. It may be oil-in-water or water-inoil type Emulsifiers can be sued to stabilize the emulsion. Soaps, detergents, proteins, and gums are used as emulsifiers. Which of the following is homogeneousA. MilkB. PaintC. ShampooD. All |
| Answer» Correct Answer - ACorrect Answer - A | |
| 43. |
There are certain substances which behave as normal, strong electrolyte at low concentration but at higher concentration they behave as colloidal solutions due to the formation of aggeregated particles. Such colloidals called associated colloids and the aggeregated particles are called micelles. The formation of micelles take place above certain concentration called critical micelization concentration called critical micellization concentration (CMC) and a characteristic temperature. Micelles areA. Emulsion-cum-gelB. Adsorbed catalystC. Associated colloidsD. Ideal solutions |
| Answer» Correct Answer - ACorrect Answer - A | |
| 44. |
There are certain substances which behave as normal, strong electrolyte at low concentration but at higher concentration they behave as colloidal solutions due to the formation of aggregated particles. Such colloids called associated colloids and the aggregated particles are called micelles. The formation of micelles take place above certain concentration called critical micellization concentration (CMC) and a characteristic temperature. Micelles are used inA. detergentsB. magnetic separationC. electrolytic refining of metalsD. All the above. |
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Answer» Correct Answer - A it si correct answer |
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| 45. |
There are certain substances which behave as normal, strong electrolyte at low concentration but at higher concentration they behave as colloidal solutions due to the formation of aggeregated particles. Such colloidals called associated colloids and the aggeregated particles are called micelles. The formation of micelles take place above certain concentration called critical micelization concentration called critical micellization concentration (CMC) and a characteristic temperature. Above CMC, the surfactant molecules undergo (more than one correct)A. AggregationB. Micelles formationC. DissociationD. All |
| Answer» Correct Answer - A::BCorrect Answer - A::B | |
| 46. |
There are certain substances which behave as normal, strong electrolyte at low concentration but at higher concentration they behave as colloidal solutions due to the formation of aggeregated particles. Such colloidals called associated colloids and the aggeregated particles are called micelles. The formation of micelles take place above certain concentration called critical micelization concentration called critical micellization concentration (CMC) and a characteristic temperature. Micelles are formed onlyA. Above `CMC` and above the Kraft temparetureB. Below `CMC` and the Kraft temparetureC. Above `CMC` and below the Kraft temparetureD. Below `CMC` and above the Kraft tempareture |
| Answer» Correct Answer - ACorrect Answer - A | |
| 47. |
There are certain substances which behave as normal, strong electrolyte at low concentration but at higher concentration they behave as colloidal solutions due to the formation of aggeregated particles. Such colloidals called associated colloids and the aggeregated particles are called micelles. The formation of micelles take place above certain concentration called critical micelization concentration called critical micellization concentration (CMC) and a characteristic temperature. Micelles are used inA. DetergentsB. Petroleum recoveryC. Magnetic separationD. All of these |
| Answer» Correct Answer - ACorrect Answer - A | |
| 48. |
There are certain substances which behave as normal, strong electrolyte at low concentration but at higher concentration they behave as colloidal solutions due to the formation of aggeregated particles. Such colloidals called associated colloids and the aggeregated particles are called micelles. The formation of micelles take place above certain concentration called critical micelization concentration called critical micellization concentration (CMC) and a characteristic temperature. What type of molecules form micelles?A. Non-polar moleculesB. polar moleculesC. Surfactnt moleculesD. Salt of weak acid and weak base |
| Answer» Correct Answer - CCorrect Answer - C | |
| 49. |
There are certain substances which behave as normal, strong electrolyte at low concentration but at higher concentration they behave as colloidal solutions due to the formation of aggregated particles. Such colloids called associated colloids and the aggregated particles are called micelles. The formation of micelles take place above certain concentration called critical micellization concentration (CMC) and a characteristic temperature. Micelles areA. emulsion cum gelsB. associated colloidsC. adsorbed catalyst stsD. ideal solutions |
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Answer» Correct Answer - B is the correct answer |
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| 50. |
In a colloidal state, the particle size of he dispersed phase ranges between `10^(3)` to `10^(6)` pm and the colloidal sol is of heterogeneous nature. Depending upon the ease with which these sols are formed, the colloidal sols are cassified as lyophilic and lyophobic. THe stability of a colloidal sol is due to the presence of charge on the sol particles and the neutralisation of the same is known as coagulation or precipitation. The coagulationg power of the active ions of he electrolytes can be compared with the help of Hardy-Schulze Law. The protecting power of the lyophilic sols can be compared with the help of gold number. Lesser the value of gold number, more will be the protecting power of the lyophilic sol. Small amount of ferric chloride `(FeCl_(3))` solution is added to freshly prepared and well washed `Fe(OH)_(3)` precipitate :A. `Fe(OH)_(3)` is dissolved forming `FeCl_(3)`B. A raddish brown positively charged sol `[Fe(OH)_(3)] Fe^(3+)` is formed due to peptasation.C. Areddish brown negatively charged sol `[Fe(OH)_(3)]:3Cl^(-)` is formed due to peptisationD. A double salt `Fe(OH)_(3).FeCl_(3)` is formed. |
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Answer» Correct Answer - B is the correct answer. |
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