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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.
| 301. |
Adsorption playso no role in :A. sugar industry to decolourise the crude sugarB. stopping bleeding from a fresh cutC. drying of the substance using anhydrous `CaCl_(2)`D. concentration of the ores by Froath floatation method. |
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Answer» Correct Answer - C Anhydrous `CaCl_(2)` has the capacity to absorb moisture on its surface as well as in the bulk. Therefore, it is a case of adsorption and not absorption. |
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| 302. |
Chromatography is based on :A. chemicl adsorptionB. physical adsorptionC. hydrogen bondingD. sedimentation. |
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Answer» Correct Answer - B Chromatography is bsed upon physical adsorption because the components are absorbed to different extent and can also be easily eluted. |
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| 303. |
On passing light from colloidal solution, the effect due to scattering of light is known as :A. electrophoresisB. tyndall effectC. electrosmosisD. coagulation |
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Answer» Correct Answer - B |
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| 304. |
The solution in which the light is scattered by the particles is :A. suspensionB. colloidal solutionC. true solutionD. none of these |
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Answer» Correct Answer - B |
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| 305. |
Cod liver oil is derived fromA. An emulsionB. SolutionC. Colloidal solutionD. Suspension |
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Answer» Correct Answer - A A colloid of liquid in liquid is called emulsion. Cod liver oil is such an emulsion. |
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| 306. |
What is absorption ? Give one example. |
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Answer» Absorption : The uniform distribution of a substance through out the bulk of the solid substance is known as absorption. Eg: Chalk stick dipped in ink. |
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| 307. |
Freundlich isotherm explains the behaviour of adsorptionA. Room temperatureB. Low pressureC. High temperatureD. High pressure |
| Answer» Correct Answer - D | |
| 308. |
Which of the following statements is incorrect?A. Physical adsorption occurs readily at low temperatureB. Physical adsorptionis characterized by small enthalpy of adsorption `(20-40 KJ mol^(-1))`C. Physicay adsorption is reversible and the adsorption equilibrium is established rapidlyD. Chemical adsorption occurs at a law temperature |
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Answer» Correct Answer - D As chemisorption involves compound formation it is usually irreversible in nature. Chemisorption, is also an exothermic process but the process is very slow at low temperature on account of high energy of activation. Like most chemical changes, chemisorption often increase with rise of temperature may change into chemisorption at a high temperature. Usually high pressure is also favorable for chemisorption. |
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| 309. |
A graph is plotted between log (x/m) and log p according to the equation `(x)/(m) kp^(1//n)` Which is the following statements about his graph is not correct ?A. The figure shows Freundlich adsorption isothermB. The figure shows Langmuir adsorption isothermC. The adsorption varies directly with pressureD. The factor 1/n can have values between 0 and 1. |
| Answer» Correct Answer - B | |
| 310. |
Which of the following statements are correct with respect to adsorption of gases on a solid ? (i) The ectent of adsorption is equal to `KP^(n)` according to Freundlich isotherm. (ii) The extent of adsorption is equal to `KP^(1//n)` according to Frendlich isotherm. (iii) The extent of adsorption is equal to (1+bP)/aP according to Langmuir isotherm. (iv) The extent of adsorption is equal to aP/(1+bP) according to Langmuir isotherm. (v) Freundlich adsorption isotherm fails at low temperature.A. (i) and (ii)B. (i) and (iv)C. (ii) and (iii)D. (ii) and (iv) |
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Answer» Correct Answer - D (ii) and (iv) are the correct options. |
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| 311. |
Cloud bursts due to :A. attraction towards the electrical charges on the earthB. large amount of water present in the cloudC. dense cloud are present in the upper atmosphereD. mutual discharge of oppositely charged clouds resulting in the coagulation. |
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Answer» Correct Answer - D Clouds are water -disperesed in air sol carrying + ve and =ve charge on water molecules . |
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| 312. |
Gelation is often used as an ingredient in the mabnufacture of ice -cream . The reason for this is :A. to statbillize the formation of a colloidB. to stabilize colloid and prevent crystal frowthC. to cause the mixure to solidigyD. to improve the filavour |
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Answer» Correct Answer - B Gelatin is protective collid . |
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| 313. |
Collidal solution is a heterogeneous solution which contains particle of intermediate size, i.e., (diameter between 1 and 1000 nm) colloidal is not a substance but it is a state of a substance which depends upon the molecular size. Colloidal solutions are intermediate between ture solution and suspensions. The colloidal particle can pass throughA. Filter paper as well can pass through Animal MembraneB. Animal membrane but not through filter paper.C. Filter paper but not through animal membrane.D. Neither filter paper nor animal membrane. |
| Answer» Correct Answer - CCorrect Answer - C | |
| 314. |
Collidal solution is a heterogeneous solution which contains particle of intermediate size, i.e., (diameter between 1 and 1000 nm) colloidal is not a substance but it is a state of a substance which depends upon the molecular size. Colloidal solutions are intermediate between ture solution and suspensions. The colloidal solution of a solid as the disperesed ohases and a gas as the dispersed medium is calledA. SolB. Sloid foamC. AerosolD. Gel |
| Answer» Correct Answer - CCorrect Answer - C | |
| 315. |
Collidal solution is a heterogeneous solution which contains particle of intermediate size, i.e., (diameter between 1 and 1000 nm) colloidal is not a substance but it is a state of a substance which depends upon the molecular size. Colloidal solutions are intermediate between ture solution and suspensions. ChemisorptionA. Increases with temperatureB. Decreases with temperatureC. Remains unaffected by change of temperature.D. First increases and then decreases. |
| Answer» Correct Answer - DCorrect Answer - D | |
| 316. |
Sodium lauryl sulphate is a :A. Cationic solB. Anionic slC. Neutral solD. None of these |
| Answer» Correct Answer - A | |
| 317. |
Which statement comparing the soap sodium stearate, and the detergent sodium lauryl sulfate is not true ?A. It has a non-polar organic part and a polar groupB. It is not easily bidegradedC. It is a sodium salt of fatty acidD. It is a surface active agent |
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Answer» Correct Answer - C `{:("Substance","Gold number"),("Gelatin",0.005-0.01),("Starch",25-50),("Albumin",0.10-0.2),("Blood (Haemoglobin)",0.03):}` |
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| 318. |
The outcome of inernal liquid of gels on shear is called :A. synetisisB. thixotropyC. swellingD. none of there |
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Answer» Correct Answer - D It is the definition of thixotropy , a property of gel . |
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| 319. |
The correct statement(s) pertaining to the adsorption of a gas on a solid surface is (are) :A. Adsorption is always exothermic.B. Physisorption may transform into chemisorption at high temperature.C. Physisorption increases with increasing temperature but chemisorption decreases with increasing temperature.D. Chemisorption is more exothermic than physisorption, however it is very slow due to higher energy of activation. |
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Answer» Correct Answer - A::B::D |
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| 320. |
The correct statement (S) pertaining to the adsorption of a gas on a solid surface is (are)A. Adsorption is always exothermicB. Physisorption may transform into chemisorption at high temperatureC. Physisorption icnreases with inincreasing temperature but chemisorption decreases with increasing temperatue.D. chemisorption is more exothermic than py sisorption, however it is very slow due to higher energy of aactivation. |
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Answer» Correct Answer - A::C In phtsisorption, with the increase in temperature extent of adsorption decreases (I). Chemisorption first increases with increase in temperature upto a certain extent and then decreases regularly thus (II) is chemisorption. Therefore, (a) is correct option. In chemisorption, attractive forces between adsorbent and adsorbate molecules are strong chemical bonds. As a result, enthalpy of adsorption is high and of the order 80-240 Kj/mol. as in IV `DeltaH_("adsorption")=150KJ//mol`l , thus it also represents chemical adsorption. Therefore (C) is also a correct option. |
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| 321. |
Choose the correct reason(s) for the stability of the lyophobic colloidal particles.A. Preferential adsorption of ions on their surface from the solutionB. Preferential adsorption of solvent on their surface from the solutionC. Attraction between different particles having opposite charges on their surfaceD. Potential difference between the fixed layer and the diffused layer of opposite charges around the colloidal particles |
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Answer» Correct Answer - A::D |
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| 322. |
The correct statement(s) pertaining to the adsorption of a gas on a solid surface is (are)A. Adsorption is always exothermicB. Physisorption may transform into chemisorption at high temperatureC. Physisorption increases with increasing temperature but chemisorption decreases with increasing temperatureD. Chemisorption is more exothermic than physisorption, however it is very slow due to higher energy of activation |
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Answer» Correct Answer - A::B::D |
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| 323. |
Assertion (A): Micelles are formed by surfactant molecules above the critical micellization concentration `(CMC)` . Reason(R): The conductivity of a solution having surfactant molecules decreases sharply at the `CMC` .A. Statement 1 is true, statmeent 2 is true, statement 2 is a correct explanation for statement 1B. Statement 1 is true, stateement 2 is true, statement 2 is not a correct explanation for statement 1C. Statement 1 is true, statement 2 is falseD. Statement 1 is false, statement 2 is true |
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Answer» Correct Answer - B At a certain concentration surfactant molecules start to ggregate and form micelle, the concentration is called critical micellisation concentration (CMC). Aggregation of surfactant molecules (ions, `RCO O^(-)`) micelle formation cause effective fall in number of free ions to conduct electricity, thus, conductivity decreases at CMC. |
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| 324. |
Statement : The plot of atomic number ( y -axis ) versus number of neutrons ( x -axis ) for stable nuclei shows a curvature towards x-axis fron the line of ` 45^@` slope as the atomic number is increased . Explanation : proton -proton electrostatic repulsions begin to overcome attracive forces involving protons and neutrons in heavier nuclides.A. Statement I is true , Statement II is true , Statement II is a correct explanation of Statement IB. Statement I is true , Statement II is true , Statement II is not the correct explanation of Statement IC. Statement I is true , Statement II is falseD. Statement I is false , Statement II is true |
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Answer» Correct Answer - A |
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| 325. |
Assertion (A): Micelles are formed by surfactant molecules above the critical micellization concentration `(CMC)` . Reason(R): The conductivity of a solution having surfactant molecules decreases sharply at the `CMC` .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 not the correct explanation of (A).C. If (A) is incorrect, but (R) is correct.D. If both (A) and (R) are incorrect. |
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Answer» Correct Answer - B Both assertion and reason are correct. A micelle of formed when a veriety of molecules such as soap and deterents are added to water. The molecule may be a fatty acid,a sltt of fatty acid (doap), phospholipid, or other similar molecule. The non-polar tails of the molecule chump into the centre of a ball-like structure called a micelle because they are hydrophobic. At some concentration, the surface becomes completely loaded with surface and any further additions arrange as micelles. This concentration is called the critical micellization concentration (CMC). This cause a decreases in the number of free ions to conduct electricity. thus conductivity decreases at CMC. |
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| 326. |
Assertion (A): Micelles are formed by surfactant molecules above the critical micellization concentration `(CMC)` . Reason(R): The conductivity of a solution having surfactant molecules decreases sharply at the `CMC` .A. Statement I is true , Statement II is true , Statement II is a correct explanation of Statement IB. Statement I is true , Statement II is true , Statement II is not the correct explanation of Statement IC. Statement I is true , Statement II is falseD. Statement I is false , Statement II is true |
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Answer» Correct Answer - B |
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| 327. |
Assertion (A): Micelles are formed by surfactant molecules above the critical micellization concentration `(CMC)` . Reason(R): The conductivity of a solution having surfactant molecules decreases sharply at the `CMC` .A. Statement 1 is True, statement 2 is True, statement 2 is a corect explanation for statement 1B. Statement 1 is True, statement 2 is True, statement 2 is a not corect explanation for statement 1C. Statement 1 is True, statement 2 is FalseD. Statement 1 is False, statement 2 is True |
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Answer» Correct Answer - B Due to aggregation of ions at `CMC` , no. of ions per unit volume decreases and hence conductivity decreases. |
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| 328. |
If `T_(k)=` Kraft temperature and CMC = Critical micelle concentration then the formation of micelles takes place only (i) Below `T_(k)` (ii) Below CMC (iii) Above `T_(k)` Above CMCA. (i) and (iv)B. (ii) and (iii)C. (iii) and (iv)D. (i) and (ii) |
| Answer» Correct Answer - C | |
| 329. |
The correct statement(s) about surface properties is (are)A. The critical temperature of ethane and nitrogen are 563K and 126K, respectively. The adsorption of ethane will more than that of nitrogen of sae amount of activated charcoal at a given temperatureB. Cloud is an emulsion type of colloid in which liquid is dispersed phase and gas is dispersion mediumC. Adsorption is accompanied by decreases in enthalpy and decrease in entropy of the systemD. Brownian motion of colloidal particles does not depend on the size of the particles but depends viscosity of the solution |
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Answer» Correct Answer - A::C Higher the critical temperature, higher will be extent of adsorption. ltBrgt Cloud is an arosol, emulsions are liquid-liquid colloidal system. For adsorption `DeltaHimplies`negative:`DeltaSimplies`negative Brownian movementof colloidal particles depends on size off particles. |
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| 330. |
In the redox reaction. `2MnO_(4)^(-)+5H_(2)O_(4)^(2-)+16H^(+)hArr2Mn^(2+)+10CO_(2)+8H_(2)O` The ion acting as autocatalyst is:-A. `MnO_(4)^(-)`B. `C_(2)O_(4)^(2-)`C. `H^(+)`D. `Mn^(2+)` |
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Answer» Correct Answer - D `Mn^(++)` is a product in reaction so it is autocatalyst (according to definition). |
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| 331. |
10 % sites of catalyst bed have adsorbed by `H_(2)` on Heating `H_(2)` gas is evloved from sites and collected at 0.03 atm and 300 K in a small vessel of `2.46 cm^(3)`. no. of sites available is `5.4 xx 10^(16) ` per `cm^(2)` and surface area is `1000 cm ^(2)` . find out the no. of suface sites occupied per molecule of `H_(2)`.A. 1B. 2C. 3D. none of these |
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Answer» Correct Answer - c |
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| 332. |
Why does physisorption decrease with increase in temperature ? |
| Answer» Correct Answer - Due to decrease in molecular attractive force between adsorbate and adsorbent. | |
| 333. |
In physisorption adsorbent does not show specificity for any particular gas because ……. .A. involved van der Waals forces are universalB. gases involved behave like ideal gasesC. enthalphy of adsorption is lowD. it is reversible process |
| Answer» Correct Answer - A | |
| 334. |
PhysisorptionA. High specifictyB. IrreversibilityC. Non-specificityD. None of these |
| Answer» Correct Answer - C | |
| 335. |
What types of forces are involved in physisorption of a gas on solid ? |
| Answer» Weak Vander waals forces are involved in physisorption of a gas on solid. | |
| 336. |
Arrange the following diagrams in correct sequence of steps involved in the mechanism of catalysis, in accordance with modern adsorption theory. A. `(i) to (ii) to (iii) to (iv) to (v)`B. `(i) to (iii) to (ii) to (iv) to (v)`C. `(i) to (iii) to (ii) to (v) to (iv)`D. `(i) to (ii) to (iii) to (v) to (iv)` |
| Answer» Correct Answer - B | |
| 337. |
How many types of adsorption are known ? What are they ? |
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Answer» Adsorption process is divided inio two types. 1) Physisorption 2) Chemisorption |
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| 338. |
STATEMENT -1 : `AL^(3+)` ions have greater precipitating power for `As_(2) S_(3)` than `Na^(+)` ions and STATEMENT -2 `As_(2)S_(3)` sol is a negatively charged sol.A. Statement -1 is True, Statement -2 is True, Statement -2 is a correct explanation for Statement - 1B. Statement -1 is True, Statement -2 is True, Statement -2 is NOT a correct explanation for Statement - 1C. Statement - 1 is True, Statement - 2 is FalseD. Statement - 1 is False, Statement - 2 is True |
| Answer» Correct Answer - B | |
| 339. |
the catalyst used in the hydrogenation of oils is :A. FeB. NiC. PtD. `V_(2) O_(5)` |
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Answer» Correct Answer - b |
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| 340. |
the fucntion of zymase is to :A. change starch into sugarB. ferment glucose to alcohol and `CO_(2)`C. change malt sugar into glucoseD. change starch into malt sugar and dextrin |
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Answer» Correct Answer - b |
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| 341. |
the conversion of maltose to glucose is possible by the enzyme :A. zymaseB. lactaseC. maltaseD. diastase |
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Answer» Correct Answer - c |
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| 342. |
The enzyme which can catalyse the conversion of glucose to ethanol isA. diastaseB. maltaseC. invertaseD. zymase |
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Answer» Correct Answer - D The zymase enzyme converts glucose into enthyl alcohol and carbon dioxide: `underset("Glucose")(C_(6)H_(12)O_(6)(aq.))overset(Zymase)(rarr)underset("Enthyl alcohol")(2C_(2)H_(5)OH_(6)(aq.))+2CO_(2)(g)` |
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| 343. |
Which of the following gas molecules have minimum value of enthalpy of chemisorption on an iron surface?A. `NH_(3)`B. `H_(2)`C. `CO`D. `C_(2)H_(4)` |
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Answer» Correct Answer - B Chemisorption is highly specific because it will only occur if there is some possitibility of chemical bonding between adsorbent and adsorbate. For example, oxygen is adsorbed on metals by virue of oxide formation. Dihydrogen gas (which is adsorbed by transition metals due to hydride formation) has minimum value of enthalpy of chemisorptions because it is neither polar (like `NH_(3),CO`) nor it has reactive `pi` bonds (like `C_(2)H_(4)`). |
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| 344. |
What is the magnitude of enthalpy of chemisorption ? Give reason for this magnitude. |
| Answer» The magnitude of enthalpy of chemical adsorption is high 80 - 240 KJ /mole. This is due to the presence of chemical bonds between gas molecules and solid surface. | |
| 345. |
Give any two applications of adsorption. |
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Answer» Applications of adsorption : a) Separation of Inert gases : Different noble gases adsorb at different temperatures on coconut charcoal. By this principle (adsorption) mixture of noble gas is separated by adsorption on coconut charcoal. b) Gas masks : Gas mask is a device which consists of activated charcoal (or) mixture of adsorbents is used by coal miners to adsorb poisonous gases during breathing. |
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| 346. |
What is the role of adsorption in froth floatation process used especially for concentration of sulphide ores? |
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Answer» In froth foatation process sulphide ore is shaken with pine oil and water, the ore particles are adsorbed on froth that floats and the gangue particles settle down in tank, role of adsorption in froth floatation process can be understood as following processes. (i) Adsorption of pine oil on sulphide ore particles. (ii) Formation of emulsion takes place. (iii) Froth is formed along with ore particles. (iv) Mechanism of the functioning of shape selective catalysis. As sulphide are extracted using froth floatation method therefore, only sulphide ore particles will show these type of adsorbing tendency. |
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| 347. |
The volume of a colloidal particle `V_C` as compared to the volume of a solute particle in a true solution `V_S` could beA. `(V_C)/(V_S)cong1`B. `(V_C)/(V_S)cong10^(23)`C. `(V_C)/(V_S)cong10^-3`D. `(V_C)/(V_S)cong10^3` |
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Answer» Correct Answer - D `(V_c)/(V_s) = (10^(-5))/(10^(-7)) ~~ 10^(3)`. |
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| 348. |
The volume of colloidal particles ` V_c` as compared ot the volume of solute particles in true solution ` V_c` could be :A. `~1`B. `~10^(23)`C. `~ 10^(-3)`D. `~10^3` |
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Answer» Correct Answer - d `V_x/V_s = (4/3 pir_c^3)/(4/3pir_s^3)=(rc^3)/(r_s^3) = ((10)/1)^3 = 1^(-3)` Diameter of slo particle `~= 1 Å`. Diameter of true solution particle `= 1Å`. |
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| 349. |
Find the value of log`(underset ("Volume of solute particles in true solution")overset("volume of colloidal particels")(_))` (In case of limiting value) |
| Answer» Correct Answer - 3 | |
| 350. |
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 In homogenous catalytic reactions, there are three alternative paths A, B, and C (shown in figure). Which one of the following indicates the relative ease with which the reaction can take place? A. `A.B.C`B. `C.B.A`C. `B.C.A`D. `A=B=C` |
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Answer» Correct Answer - B Activation energy in the different path lies in the following sequence: `CltBltA` Lesser is the activation energy, greater is the ease with which the reaction can take place. `:. CgtBgtA` (Decreasing ease with which the reaction can take place.) Correct Answer - B Activation energy in the different path lies in the following sequence: `CltBltA` Lesser is the activation energy, greater is the ease with which the reaction can take place. `:. CgtBgtA` (Decreasing ease with which the reaction can take place.) |
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