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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.
| 651. |
`As_(2)S_(3)` sol is ,A. postivie colloidB. negative colloidC. neutral colloidD. none of the above |
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Answer» Correct Answer - b |
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| 652. |
Adsorption is the phenomenon in which a substanceA. accumulates on the surface of the other substanceB. goes into the body of the other substanceC. remains close to the other substanceD. None of the above . |
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Answer» Correct Answer - A Adsorption is the phenomenon in which a substance accumulates on the surface of the other substance. |
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| 653. |
Adsorption is the phenomenon in which a substance :A. accumulates on the surface of the other substanceB. goes into the body of the other substanceC. remain close to the other substanceD. none of these |
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Answer» Correct Answer - A Accumulation substantce on the surface of the other substance is known as adsorption. |
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| 654. |
Adsorption is the tendency of accumulation of molecular species at the surface of solid or liquid. Depending upon the nature of bonds or forces of attraction between adsorbate and adsorbent. It is classofied between physisorption and chemisorption. Which of the following gas molecules have maximum value enthalpy of physisorption?A. `C_(2)H_(6)`B. `Ne`C. `H_(2)`D. `H_(2)O` |
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Answer» Correct Answer - D Since `H_(2)O` can be liquified easily. Hence it will have maximum enthalpy of physisorption. Correct Answer - D Since `H_(2)O` can be liquified easily. Hence it will have maximum enthalpy of physisorption. |
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| 655. |
Collidal dispersion have been classified into different types depending upon the physical state of the dispersed phases and the dispersion medium. They are prepared in the industry or in the laboratory by a number of methods and then purified. The protective action of lyophilic colloids was studied by Zsigmondy and he introduced a term called gold number. Which of the following has minimum gold number?A. AlbumenB. GelatinC. StarchD. Gum arabic |
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Answer» Correct Answer - B Gelatin has minimum gold number and hence highest protective power. Correct Answer - B Gelatin has minimum gold number and hence highest protective power. |
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| 656. |
Adsorption is the tendency of accumulation of molecular species at the surface of solid or liquid. Depending upon the nature of bonds or forces of attraction between adsorbate and adsorbent. It is classofied between physisorption and chemisorption. Which of the following gases is adsorbed most by activated charcoal?A. `CO_(2)`B. `N_(2)`C. `Ar`D. `C_(2)H_(6)` |
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Answer» Correct Answer - A `CO_(2)` is an easily liquefiable gas, hence it is adsorbed most by charcoal. Correct Answer - A `CO_(2)` is an easily liquefiable gas, hence it is adsorbed most by charcoal. |
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| 657. |
How does `BF_(3)` act as a catalyst in industrial process? |
| Answer» `BF_(3)` is a strong Lewis acid. Hence, it is used as a catalyst in industrial processes. `BF_(3)` is a strong Lewis acid. Hence, it is used as a catalyst in industrial processes. | |
| 658. |
Which of the following is an example of heterogeneous catalysis ?A. `4NH_(3) + 5O_(2) overset(Pt)to 4NO +6H_(2)O`B. `2SO_(2) + O_(2) overset(NO)to 2SO_(3)`C. `CH_(3)COOCH_(3) + H_(2)O overset (HCl)to CH_(3)COOH + CH_(3)OH`D. `C_(12)H_(22)O_(11) + H_(2)O overset(H_(2)SO_(4))to C_(6)H_(12)O_(6)+C_(6)H_(12)O_(6)` |
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Answer» Correct Answer - A This is an example of heterogeneous catalysis as the catalyst is present in different phase than that of the reactants. |
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| 659. |
Shape Selective Catalysis By Zeolites |
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Answer» The catalystic reaction which depends upon the pore size of the catalyst and the size of the reactant and product molecules is called shape-selective catalysis. Zeolites are good shape-selective catalysts because of their honey comb like structures. ZSM-5 is used in petroeum industry to convert alcohols directly into gasoline by dehydrating them to give a mixture of hydrocarbons. `xCH_(3)-Ooverset(ZSM-5)(rarr)underset("Gasoline")((CH_(2))_(x))+xH_(2)O` The catalystic reaction which depends upon the pore size of the catalyst and the size of the reactant and product molecules is called shape-selective catalysis. Zeolites are good shape-selective catalysts because of their honey comb like structures. ZSM-5 is used in petroeum industry to convert alcohols directly into gasoline by dehydrating them to give a mixture of hydrocarbons. `xCH_(3)-Ooverset(ZSM-5)(rarr)underset("Gasoline")((CH_(2))_(x))+xH_(2)O` |
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| 660. |
Which of the followign statements about zerolites is not correct ?A. Zeolites are open structures of silica in which trivalent aluminium is substituted by a fraction of silicon atoms.B. Shape selectivity of zeolites depends upon porous structure of the catalystC. Zeolites are synthetic microporous aluminosilicates which do not exist naturally.D. Zeolites are aluminosilicates having three dimensional network. |
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Answer» Correct Answer - C Zeolites are naturally occuring or synthetic microporous aluminosilicates. |
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| 661. |
The cementation process is :A. gel formationB. emulsion formationC. either of themD. none of these |
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Answer» Correct Answer - A Water molecules are held up in solid cement particles to given gel formation . |
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| 662. |
Silica gel is commorbly used as :A. wetting agentB. drying agentC. solventD. catalyst |
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Answer» Correct Answer - B Silica gel si a powerful adsorbent for moisture . |
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| 663. |
At `CMC`, the surfactant molecules undergoes :A. associationB. aggergationC. micelle formationD. all of these |
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Answer» Correct Answer - D All are same processes . |
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| 664. |
The potential differnce between the fixed particles layer and the fiffused layer having oppositoe charge id called :A. zeeta potentialB. colloidal potentialC. streaming potentialD. dorn potential |
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Answer» Correct Answer - A The definition of Zeeta potential . |
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| 665. |
The ability of ion to bring about coagulation of a given collidal solution depends uponA. its size of ionB. the magnitude of chargeC. the sign of chargeD. Both magnitude and sign of charge |
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Answer» Correct Answer - D Both magnitude and sign of charge. |
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| 666. |
Which one of the following is a nature colloid?A. Sodium chloide solutionB. Cane sugar solutionC. Urea solutionD. Blood |
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Answer» Correct Answer - D Blood is a natural colloid. |
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| 667. |
Gold number of a lyphilic sol is such property that:A. the larger its value, the greater is the peptisting powerB. the lower its value, the greater is the peptisting powerC. the lower its value, the greater is the protecting powerD. the larger its value, the greater is the protecting power |
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Answer» Correct Answer - C Gold number `prop (1)/("protecting power")` |
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| 668. |
Gold number of a lyphilic sol is such property that:A. that larger its value, the greater is the peptising powerB. the lower its value, the greater is the peptising powerC. the lower its value, the greater is the protecting powerD. the larger its value, the greater is the protecting power |
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Answer» Correct Answer - C |
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| 669. |
What is electrophoresis ? |
| Answer» When electric potential is applied across two platinum electrodes dipping in a colloidal solution, the colloidal particles move towards one or the other electrode. The movement colloidal particles under an applied emf is called "electrophoresis". | |
| 670. |
At what PH range the rate of enzyme catalyzed reaction is maximum ?A. 5 to 7B. 6 to 8C. 7 to 9D. 8 to 9 |
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Answer» Correct Answer - a |
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| 671. |
Name any two enzyme catalyzed reactions. Give the reactions |
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Answer» 1) Inversion of Cane sugar : `underset("Cane Sugar")(C_(12)H_(22)O_(11_((aq)))) + H_(2)O_((l)) overset("Invertage")to underset("Glucose")(C_(6)H_(12)O_(6_((aq)))) + underset("Fructose")(C_(6)H_(12)O_(6_((aq))))` 2) Decomposition of urea into ammonia and `CO_(2)` `NH_(2)CONH_(2_((aq))) + H_(2)O_((l)) overset("Urease")to 2NH_(3_((g))) + CO_(2_((g)))` |
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| 672. |
Hydolysis of cane sugar is catalysed by :A. ` H^+`B. mineral acidsC. enzymesD. all of these |
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Answer» Correct Answer - D `H^+` form weak acids or strong acids or enzyme `s invertase catalyst the hydrolysis of sugar . |
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| 673. |
Which is false for catalyst ?A. A catalyst can initiate a reactionB. It does not alter the positon of the equilibrium in a reversible ractionC. A catalyst remains undcharged compositon at the end if the reactioD. Catalyste are sometimes very specific in respect of a reacton |
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Answer» Correct Answer - A Catalyst never starts a chemical reaction . It simply speeds up reaction . |
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| 674. |
Which is false for catalyst ?A. A catalyst can initiate a reactionB. It does not alter the position of equilibrium in a reversible reactionC. A catalyst remains unchanged in quality and composition at the end of reactionD. Catalysts are sometimes very specific in respect of a reaction |
| Answer» Correct Answer - A | |
| 675. |
Identify the option correctly representing True/False nature of the statements. Statement-1: Changing the catalyst can change the final product obtained in some reaction. Statement-2: Catalyst cannot change equilibrium constant of a reaction. Statement-3: Lacto bacilli enzyme is responsible for curd formation from milk. Statement-4: A promotor when taken without catalyst will always increase rate of reaction.A. All are true.B. Statement-4 is the only false statement.C. Statement-2 and Statement-3 are the only true statements.D. All are incorrect. |
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Answer» Correct Answer - B |
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| 676. |
Which is an example os autro-catalysis ?A. Decompositon of ` KCiO_3 + MnO_2` mnixtureB. The decomposition of nitroglycerineC. Breakdown of ` _6C^(14)`.D. Hydrogenation of vegetable oils using Ni catalyst |
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Answer» Correct Answer - B It releases a large volume of gases during its explosion as ` 4 C_3 H_5 (ONO_2) rarr 12CO_2 + 1 0 H_2 O + 6N_2 +O_2` ltbRgt The gaseous mixture acts as auto-catalyst . |
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| 677. |
Which statement about enzymes is not corect ?A. Enzymes are in coloidal stateB. Enzymes are catalystsC. Enzymes can catalyes any reactionD. a |
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Answer» Correct Answer - C Enzyme catalysed reactions are highly specificl in nature. This means that the same enzyme cannot catalyes all the reactons. |
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| 678. |
Statements : A collode gets coagulated by addition of an electrolyte . . Expabnations : The rate of coagultion depends on the magnitude and sing of the charge of the coagulant ion.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 - D Statement and exphantion are correct buyt does not give correct explanation are correct hut does not give correc explanation . |
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| 679. |
A substance is analyzed by paper chromatography, giving the chromatogram shown. What is the `R_(f)` value of the substance represented by the spot at 8.0 cm?A. `0.80`B. `0.75`C. `0.67`D. `0.60` |
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Answer» Correct Answer - B |
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| 680. |
The stabilization of a lyophobic colloid is due to :A. Adsorption of covalent molecules on colloidB. Size of particlesC. Charge on the particlesD. Tyndall effect. |
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Answer» Correct Answer - C it is the correct answer. |
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| 681. |
…….. Is the gold number of hydrophilic colloid, greater is its protective power.A. higherB. lowerC. constantD. non of these. |
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Answer» Correct Answer - B it is the correct answer. |
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| 682. |
Give two examples of lyophobic sols. |
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Answer» Metal sols and metal sulphide sols are examples of lyophobic colloids `to` Gold sol is lyophobic colloid |
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| 683. |
Give examples of colloidal system of Liquid in solid . |
| Answer» Cheese, butter, jellies are examples of liquid in solid type colloidal system. | |
| 684. |
Give examples of colloidal system of Gas in solid. |
| Answer» Foam rubber, pumice stone are examples of gas in solid type of colloidal system. | |
| 685. |
Indicate a chemical reaction involving a homogeneous catalyst. |
| Answer» `2SO_(2)(g)+O_(2)(g)overset(NO(g))(rarr)2SO_(3)(g)` .`2SO_(2)(g)+O_(2)(g)overset(NO(g))(rarr)2SO_(3)(g)` . | |
| 686. |
A negative catalyst will :A. raise the energy of activation for a given reactionB. take away the internal energy of reactants and deactivate themC. catalyse the backward reaction more than the forward one, thereby shifting equilibrium backwardD. none of these |
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Answer» Correct Answer - A |
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| 687. |
A negative catalyst willA. raise the energy of activation for a given reactionB. take away the international energy of reactants and deactivate themC. catalyst the backward reaction more than the forward one, thereby shifting equilibrium backward.D. none of these |
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Answer» Correct Answer - B Negative catalyst provides a path of higher activation energy |
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| 688. |
Which of the following is a mismatch :A. Lyophilic colloids - reversible solsB. Associated colloids - micellesC. Tyndall effect - scattering of light by colloidal particleD. Electrophoresis - movement of dispersion medium under the influence of electric field |
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Answer» Correct Answer - D Electrophoresis means movement of colloidal particles under the influence of electric field. |
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| 689. |
Which of the following ions has maximum flocculation value?A. `[Fe(CN)_(6)]^(4-)`B. `Cl^(-)`C. `SO_(4)^(2-)`D. `PO_(4)^(3-)` |
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Answer» Correct Answer - B |
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| 690. |
What is an emulsion ? Give two examples. |
| Answer» Emulsion : The colloidal system in which a dispersion of finely divided droplets of a liquid in another liquid medium is called emulsion. Eg : Milk, Vanishing cream, Cold cream. | |
| 691. |
Which of the following is known as a Ziegler-Natta catalyst ?A. `TiCl_(2)//AlCl_(3)`B. `FeSO_(4)//H_(2)O_(2)`C. `TiCl_(4)//Al(C_(2)H_(5))_(3)`D. `AlCl_(3)//CuCl_(2)` |
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Answer» Correct Answer - C It is capable of catalyzing the polymerization of ethene and propene at normal temperature and pressure. |
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| 692. |
Which of the following is known as a Ziegler-Natta catalyst ?A. `TiCl_(3)+Al(C_(2)H_(5))_(3)`B. `TiCl_(4)+Al(C_(2)H_(5))_(3)`C. `Ti(C_(2)H_(5))_(3)+AlCl_(3)`D. `Ti(C_(2)H_(5))_(4)+AlCl_(3)` |
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Answer» Correct Answer - B `underset("Propylene")(nCH_(3))-CH=CH_(2) overset((CH_(3)CH_(2))_(3)Al+TiCl_(4))(rarr) overset("Polypropylene")([-CH_(2)-overset(CH_(3))overset(|)(C)H-]_(n)) |
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| 693. |
A catalyst is used toA. Increase the productB. Increases or decrease the rate of reactionC. increases or decrease the productsD. Decreases the products |
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Answer» Correct Answer - B Catalyst is a substance which change the rate of reaction without affecting the overall energetics of the reaction. |
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| 694. |
Hydorlysis of ethyl acetate is catalysed by aqueousA. `Na_(2)SO_(4)`B. `K_(2)SO_(4)`C. `H_(2)SO_(4)`D. `BaSO_(4)` |
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Answer» Correct Answer - C `CH_(3)COOC_(2)H_(5)+HOH underset(Catelyst)overset(Conc.H_(2)SO_(4))(rarr)CH_(3)COOH+C_(2)H_(5)OH` |
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| 695. |
A catalystA. Increase the free energy change in the reactionB. Decrease the free energy change in the reactionC. Does not increase or decrease the free energy change in the reactionD. can either increase or decrease the free energy change depending on what catalyst we use |
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Answer» Correct Answer - C Catalyst does not depeded on the free energy change in the reaction. |
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| 696. |
Identify the appropriate graph between enthalpy and progress of physical adsorption.A. B. C. D. |
| Answer» Correct Answer - A | |
| 697. |
Hydrolysis of ester in catalysed by acid. Rate of hydrolysis of ester were obtained initially and after some ester has been hydrolysed as `R_(0)` and `R_(t)` then (same temp.)A. `R_(0) = R_(t)`B. `R_(0) lt R_(t)`C. `R_(0) gt R_(t)`D. Cannot be determined |
| Answer» Correct Answer - B | |
| 698. |
For the coagulation of `100 mL` of arsenious sulphite `sol,5 mL` of `1 M NaCl` is required. What is the flocculaton value of `NaCl`? |
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Answer» `5mL` of `1MNaCl` contains `NaCl=(1)/(1000)xx5mol=5m mol` Thus, `100mL` of `As_(2)S_(3)sol` require `NaCl` for complete, coagulation `=5m mol` `:.` 1L, i.e., `1000mL` of the sol requires `NaCl` for complete, coagulation `=50m mol` Therefore, the flocculation value of `NaCl=50` `5mL` of `1MNaCl` contains `NaCl=(1)/(1000)xx5mol=5m mol` Thus, `100mL` of `As_(2)S_(3)sol` require `NaCl` for complete, coagulation `=5m mol` `:.` 1L, i.e., `1000mL` of the sol requires `NaCl` for complete, coagulation `=50m mol` Therefore, the flocculation value of `NaCl=50` |
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| 699. |
The movement of colloidal particles under an applied electrical potential is calledA. PrecipitationB. StabilisationC. ElectrophoresisD. Brownian movement |
| Answer» Correct Answer - C | |
| 700. |
Which of the following statements is correct?A. If freshly formed precipitate of stannic oxide is peptized by a small amount hydrochloric acid, the sol carries a positive charge but if peptized by a small amount of sodium hydroxide, the sol carries a negative cahrge.B. If a dilute solution of silver nitrate is added to a slight excess of a dilute solution of potassium iodide, a negatively charged sol of silver iodide is formed. But if a dilute solution of potassium iodide is added to a slight excess of dilute solution of silver nitrate, a positively charged sol of silver iodide is formedC. If Fe `Cl_(3)` is added to excess of hot water, a positively charged sol of hydrated ferric oxide is formed by when ferric chloride is added to `NaOH`, a negatively charged sol is obtained.D. All of these |
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Answer» Correct Answer - D When two or more ions are present in the disperison medium, preferential adsorption of the ion common to the colloidal particle usually takes place. In the former case of stannic oxide, a small amount of stannic chloride, `SnCl_(4)` is formed and the positively charged `Sn^(4+)` ion is prefferred and sol is positively charge, In the latter cse, a small amount of sodium stanate, `Na_(2)SnO_(3)` is preferred and accordingly the sol is negatively charged. The chloride and sodium ions known as counter ions, are directed towards the liquid phase. When silver nitrate solution is added to a slight excess of postassium iodide solution, the precipitated silver iodide adsorbs iodide ions (present in excess) from the dispersion medium and negatively charged colloidal solution results. But when `KI` solution is added to a sight excess of `AgNO_(3)` solution, positively charged sol result due to adsorption of `Ag` ions (present in excess) from dispersion medium. `{:(AgI//I^(-),AgI//Ag^(+)),("Negatively charged","Positively charged"):}` However, if silver nitrate and sodium iodide are mixed in equivalent amounts, there is precipitation of silver iodide and no sol is formed due to absence of charges. Once again the ions preferred by colloidal particle are those which are common to them. Thus, in the former case, silver iodide prefers iodide ion and not sodium ion. Similarly in the latter case, it prefers silver ion and not nitrate ion. The counter ion in each case is directed towards the liquid phase (dispersion medium). If `FeCl_(3)` is added to excess of hot water, a positively charged sol of hydrated ferric oxide is formed due to adsorption of `Fe^(3+)` ions. But when ferric chloride is adde to `NaOH`, a negatively charged sol is obtained with adsorption of `OH^(-)` ions. `underset("Positively charged")(FeO_(3).xH_(2)"O"//Fe^(3+)) , underset("Negatively charged")(Fe_(2)O_(3).x H_(2)"O"//"OH"^(-))` |
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