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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.
| 1151. |
A solid acts as an adsorbent because it hasA. A definite shapeB. Small pores in itC. Unsaturated valenciesD. A high lattice energy |
| Answer» Correct Answer - C | |
| 1152. |
A `1 cm xx 1 cm` square paper coated with a suitable adsorbent on both sides. The paper is dipped in a aqueous solution of glucose of volume 20 mL and concentration 20 ppm. Final concentration glucose was dropped to 19 ppm due to adsorption. Find the number of glucose particles per unit area of the paper. |
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Answer» Correct Answer - `3.33 xx 10^(16) cm^(-2)` Mass of glucose adsorbed `= (20 - 19) xx (20)/(10^(6)) = 2 xx 10^(-5) g.` Moles of glucose adsorbed `= (2 xx 10^(-5))/(180) = (10^(-6))/(9).` Number of glucose molecules `= (10^(-6))/(9) xx 6 xx 10^(23) = (20)/(3) xx 10^(16)` Number of glucose molecules per unit area `= (1)/(2) xx (20)/(3) xx 10^(16) = 3.33 xx 10^(16) cm^(-2).` |
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| 1153. |
Gold number givesA. The amount of gold present in the colloidB. the amount of gold required to break the colloidC. The amount of gold required to protect the colloidD. None of these |
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Answer» Correct Answer - D Gold no. is a measure of protective power of a lyophilic colloid. |
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| 1154. |
Select the only correct option `Fe(OH)_(3)` sol.A. (I) (iii) (Q)B. (IV) (i) (Q)C. (I) (iii) (R)D. (IV) (iv) (S) |
| Answer» Correct Answer - B | |
| 1155. |
The equation for Freundlich adsorptin isotherm isA. `"log " ((x)/(m)) = "log " K + (1)/(n) " log " C`B. `"log " ((x)/(m)) = "log " m + (1)/(m) " log " C`C. `"log " ((x)/(m)) = "log " C + (1)/(K) " log " C`D. `"log " ((x)/(m)) = "log " C + (1)/(n) " log " K` |
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Answer» Correct Answer - A According to Freundlich isotherm : `(x)/(m) = Kp^(1//n)` or `"log " (x)/(m) = " log " K + (1)/(n) " log " P` (For solution, P = C). |
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| 1156. |
Which of the following is not represented by sols?A. AbsorptionB. Tyndall effectC. FlocculationD. Paramagnetism |
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Answer» Correct Answer - D Absorption, Tyndall effect and flocculation all are related to sol but paramagnetism is not represented by sol. |
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| 1157. |
On addition of `1 mL` solution of `10% NaCl` to `10 mL` gold sol in the presence of `0.0250 g` of starch, the coagulation is just prevented. What is the gold number of starch? |
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Answer» Amount of starch required `= 0.025 gm` `= 0.025 xx 10^(3) mg` `= 25 mg` Gold Number `= 25.` |
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| 1158. |
Which of the following is the best protective colloid?A. Potato starchB. Gurn arabicC. Egg albumenD. Gelatine |
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Answer» Correct Answer - D Protective power of of lyophilic colloid `prop(1)/("Gold number of lyophilic colloid")` Thus smaller the gold number of a colloid, larger will be its protective power, Gelatine having the minimum gold number is the best protective colloid. |
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| 1159. |
Which of the following can act as protective colloids?A. Hydrophilic solsB. Hydrophilic solC. Gold solD. None of these |
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Answer» Correct Answer - B Hydrophilic sol can act as protective colloids for hydrophobic solution. |
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| 1160. |
The equation for Freundlich adsorptin isotherm isA. `(x)/(m)=kp^(1//n)`B. `x=mkp^(1//n)`C. `x//m=kp^(-n)`D. All of these |
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Answer» Correct Answer - D `(x)/(m)=kp^(1//n)` or `x=m.kp^(1//n)` or `x//m=kp^(-n)` All of these equation represent Freundlich adsorption isotherm. |
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| 1161. |
During electro-osmosis of `Fe(OH)_(3)` sol a. Sol particles move towards anode b. Sol particles move towards cathode c. The dispersion medium move towards anode d. The sol particles do not move in either directionA. sol particles move towards anodeB. sol particles move towards carhodeC. the dispersion medium move towards anodeD. the dispersion medium moves towards cathode |
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Answer» Correct Answer - c |
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| 1162. |
During electro`-`osmosis of `Fe(OH)_(3)` sol `:`A. sol particles move towards anodeB. sol particles move towards cathodeC. the dispersion medium moves towards anodeD. the dispersion medium moves towards cathode |
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Answer» Correct Answer - 3 In electro-osmosis, the sol particles are prevented from migration whereas the dispersion medium migrates in the direction opposite to those of particles. Here, the medium is negatively charged. |
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| 1163. |
Which of the following will have the highest coagulating power for `Fe(OH)_(3)` colloid?A. `PO_(4)^(3-)`B. `SO_(4)^(2-)`C. `Ca^(2+)`D. `Al^(3+)` |
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Answer» Correct Answer - 1 `Fe(OH)_(3)` is a positive sol. Hence, greater the charge on Anion, more is the coagulation power. |
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| 1164. |
On addition of `1 mL` solution of `10% NaCl` to `10 mL` gold sol in the presence of `0.0250 g` of starch, the coagulation is just prevented. What is the gold number of starch?A. 25B. `2.5`C. `0.25`D. `0.025` |
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Answer» Correct Answer - A Gold number of lyophillic sol added in Mg in 10 ml gold sol with 1 ml of 10% NaCl to prevent cagulation. `=0.025 g` `0.025xx1000=25 Mg` |
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| 1165. |
Toilet soapt is a mixture ofA. Calcium and sodium salts of fatty acidsB. Fatty acids and glycerolC. sodium salts of fatty acidsD. potassium salt of fatty acids |
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Answer» Correct Answer - D Toilet soap is a mixture potassium salt of higher fatty acids. |
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| 1166. |
The gold numbers of protective colloids `A, B, C,` and `D` are `0.04, 0.002, 10` , and `25` , respectively. The protective powers of `A, B, C` , and `D` are in the orderA. A gt B gt C gt DB. B gt A gt C gt DC. D gt C gt B gt AD. C gt A gt B gt D |
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Answer» Correct Answer - B `uarr` Gold number `darr` protective power |
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| 1167. |
The gold numbers of protective colloids `A,B,D` and `D` are `0.04,0.004,10` and 40 respectively. The protective powers of `A,B,C,` and `D` are in the order `:`A. `AgtBgtCgtD`B. `BgtAgtCgtD`C. `DgtCgtAgtB`D. `DgtCgtBgtA` |
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Answer» Correct Answer - 2 Smaller is the gold number of protective colloid, greater is its protective power. |
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| 1168. |
Which of the following ions is most effective in the coagulation of an arsenious suphide solution?A. `K^(+)`B. `Mg^(2+)`C. `Al^(3+)`D. `C` |
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Answer» Correct Answer - C Effectivenss of ion in coagulation `prop` charge on coagulating ion. |
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| 1169. |
Electro - osmosic is observed when :A. disperion medium partcles begins to move in an electric fieldB. dispersed phase to move in an electric fieldC. both (a) and (b)D. none of these |
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Answer» Correct Answer - a |
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| 1170. |
The density of gold is 19`g//cm^(3)`. If 1.8`xx10^(-4)`g of gold is dispersed in one litre of water to give a sol having spherical gold particles of radius 10 nm, then the number of gold particles per `mm^(3)` of the sol will be:A. `1.9xx10^(12)`B. `6.3xx10^(14)`C. `6.3xx10^(10)`D. `2.4xx10^(6)` |
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Answer» Correct Answer - D Volume of the gold dispersed in one litre water`=(mass)/(density)` `=(1.9xx10(-4)gm)/(19" gm "cm^(-3))=1xx10^(-5)cm^(3)` Radius of gold sol particle `=10nm=10xx10^(-9)m` `=10xx10^(-7)cm=10^(-6)cm` Volume of the gold sol particle `=(4)/(3)pir^(3)` `=(4)/(3)xx(22)/(7)xx(10^(-6))^(3)=4.19xx10^(-18)cm^(3)` No. of gold sol particle in `1xx10^(-5)cm^(3)=(1xx10^(-5))/(4.19xx10^(-18))` No. of gold sol particle in one `nm^(3)` `=(2.38xx10^(12))/(10^(6))=2.38xx10^(6)`. |
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| 1171. |
To measure the protective action of action of different lyophilic sols quantitatively, the gold number was introduced by Zsig-mondy. It is defined as the minimum number of dry protective colloid which much be added to `10ml` of a specially prepared red gold sol just to prevent a change to vlolet (i.ie an incease in particle size) on the addition of `1ml` of `10` precent sodium chloride solution.A. millimolesB. gramsC. milligramsD. moles |
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Answer» Correct Answer - C The weight in milligrams of protective colloid that prevents the coagulation of `10mL` of a given sol on adding `1mL` of a `10%` solution `NaCl` is called gold number. |
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| 1172. |
The gold number of `A,B,C and D` or `0.04, 0.002, 10 and 25` respectively. Protective power of `A,B,C, andD` are in orderA. `AgtBgtCgtD`B. `BgtAgtCgtD`C. `DgtCgtBgtA`D. `CgtAgtBgtD` |
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Answer» Correct Answer - D protective power `prop (1)/("Gold number")` Hence the correct order of protective powr is `B gt A gt C gt D`. |
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| 1173. |
which of the following is a lyophobic colloid ?A. GelatinB. sulphurC. starchD. Gum arabic |
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Answer» Correct Answer - b |
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| 1174. |
Which of the following ions is most effective in the coagulation of an arsenious suphide solution?A. `K^(+)`B. `Mg^(2+)`C. `Al^(3+)`D. `Cl^(-)` |
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Answer» Correct Answer - C |
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| 1175. |
A colloid is aA. Homogeneous systemB. Heterogeneous systemC. Both (1) & (2)D. Pure matter |
| Answer» Correct Answer - B | |
| 1176. |
Protective sols are:A. lyophilicB. lyophobicC. both (a) and (b)D. none of these |
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Answer» Correct Answer - a |
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| 1177. |
Protective sols are :A. lyophilicB. lyophobicC. both (A) and (B)D. none of (A) and (B) |
| Answer» Correct Answer - A | |
| 1178. |
Protective sols are:A. lyophilicB. lyophobicC. both (a) and (b)D. none of (a) and (b) |
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Answer» Correct Answer - A |
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| 1179. |
The density of gold is `19 g//cm^(3)`. If `1.9xx10^(4)` of gold is dispersed in one litre of water to give a sol having spherical gold particles of radius `10nm`, then the number of gold particles per `mm^(3)` of the sol will beA. `1.9xx10^(12)`B. `6.3xx10^(14)`C. `6.3xx10^(10)`D. `2.4xx10^(6)` |
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Answer» Correct Answer - D Volume of the gold dispresed in one litre water `=("mass")/("density") = (1.9xx10^(-4)g)/(19g cm^(-3)) = 1 xx 10^(5)cm^(-3)` Radius of gold sol particle `=10nm = 10 xx 10^(-9)m = 10xx10^(-7) cm = 10^(-6)cm` Volume of gold sol particle = `4/3 pi r^(3)` `4/3 xx 22/7 xx (10^(-6))^(3) = 4.19xx10^(-18) cm^(3)` No. of gold sol particle in `1 xx 10^(-5)cm^(3)` No, of gold sol particle in `1 xx 10^(-5) cm^(3)` `=(1xx10^(-5))/(4.19xx10^(-18)) = 2.38xx10^(12)` No. of gold sol particle in one `mm^(3)` `=(2.38xx10^(12))/(10^6) = 2.38 xx 10^(6)`. |
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| 1180. |
The size of a colloidal particle is :A. `gt 0.1 mu`B. `1 m mu " to "0.1 mu`C. `lt 0.1 mu`D. more than `3000 m mu` |
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Answer» Correct Answer - B |
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| 1181. |
What are emulsion ? How are they classified ? Describe the applications of emulsions. |
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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. In Milk, the droplets of a liquid fat are dispersed in water. This is an example for oil in water type emulsion. Classification of emulsions : Emulsions are classified into two classes. These aer a) Oil in water (O/W) and b) Water in Oil (W/O) , (O=Oil, W=Water) These emulsions are classified as such depending on which is dispersed phase is oil and the dispersion medium. a) Oil in Water (O/W) type emulsions : In This type of emulsions , the dispersed phase is oil and the dispersion medium is water. Ex : Milk , liquid, fat (oil) in water Vanishing cream, fat in water. b) Water in Oil (W/O) type emulsions : In this type of emulsions, the dispersed phase is water and the dispersion medium is oil Ex : Stiff greases : Water in lubrication oils. Cod liver oil : water in cod liver oil Cold cream : water in fat. Applications of Emulsions : Emulsions are useful `to` In the digestion of fats in intestines. `to` In washing processes of clothes and crockery. `to` In the preparation of lotions, creams , ointments in pharmaceutical and cosmetics . `to` In the extraction of metals (froth floatation). `to` In the conversion of cream into butter by churing `to` To break oil and water emulsions in oil wells. `to` In the preparation of oily type of drugs for easy adsorption to the body. |
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| 1182. |
All colloids :A. are suspensions of one phase in anotherB. are two - phase systemsC. contain only water - soluble particlesD. are true solutions |
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Answer» Correct Answer - b |
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| 1183. |
Milk is a colloid in whichA. A liquid is dispersed in liquidB. A solid is dispersed in liquidC. A gas dispersed in a liquidD. Some sugar is dispersed in water. |
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Answer» Correct Answer - A Milk is a emusion of (liquid in liquid). |
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| 1184. |
Distinguish between the meaning of the terms adsorption and absorption. Given one example of each. |
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Answer» This phenomenon of attracting and retaining the molecules of a substance by a solid (or a liquid) on its surface resulting into a higher concentration of the molecules on the surface is known as adsorption. Absorption is different from adsorption. In absorption, the substance is uniformly distributed throughout the body of a solid or a liquid. `NH_(3)` gets adsorbed on the charcoal where as `NH_(3)` when comes in contact with `H_(2)O` gets absorbed by forming `NH_(4)OH` solution of uniform concentration. |
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| 1185. |
collodial systems are not classified on the basis of :A. molecular sizeB. nature of the particlesC. suface tension valueD. interaction between disperse phase and dispersion medium |
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Answer» Correct Answer - c |
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| 1186. |
Colloides may be classified on the basis of types of particles of the dispersed phase intoA. Lyophilic colloids and lyophobic colloidsB. Sol, gel, aerosol, emulsion etcC. Multimolecular, macromolecular and associated colloidsD. Recersible and irreversible colloids |
| Answer» Correct Answer - C | |
| 1187. |
Tyndall effect in colloidal solution is due toA. Scattering of lightB. Reflection of lightC. Absorption of lightD. Presence of electrically charged particles |
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Answer» Correct Answer - A Due to scattering of light. |
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| 1188. |
Mark the incorrect combination out of the following examples of colloidal solutions .A. `{:("Colloid","Dispresion medium","Dispered phase"),("Smoke","Gas","Solid"):}`B. `{:("Colloid","Dispresion medium","Dispered phase"),("Mist","Gas","Liquid"):}`C. `{:("Colloid","Dispresion medium","Dispered phase"),("Gel","Liquid","Liquid"):}`D. `{:("Colloid","Dispresion medium","Dispered phase"),("Emulsion","Liquid","Liquid"):}` |
| Answer» Correct Answer - C | |
| 1189. |
Among the following , select the properties pf lyophilic coloidal sols :A. viscostiy same as that of the mediumB. extensive hydration takes placeC. particle migrate either towards cathode or anode in an electric fieldD. particle can be readly detected under ultramicroscope |
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Answer» Correct Answer - b |
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| 1190. |
Which of the following is (are) lyophobic colloids?A. Gold solB. `As_(2)S_(3)sol`C. Starch solD. `Fe(OH)_(3)` sol |
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Answer» Correct Answer - A::B::D |
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| 1191. |
Blue rock salt is classified asA. solid dispersed in a solid dispersion mediumB. liquid dispersed in a liquid dispersion mediumC. liquid dispersed in a solid dispersion mediumD. solid dispersed in a liquid dispersion medium |
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Answer» Correct Answer - A Colored glasses and gem stones are examples of solid sols. |
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| 1192. |
In a process , adsorption and absorption take place together. This is defined byA. desorptionB. adsorptionC. sorptionD. absorption |
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Answer» Correct Answer - C when adsorption and adsorption take place together, it is called sorption. Desorption is reversed of adsorption. |
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| 1193. |
Small liquid droplets in another liquid is calledA. SuspensionsB. emulsionC. GelD. True solution |
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Answer» Correct Answer - B Liquid in liuqid is known as emulsion. |
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| 1194. |
which of the following is an example of assiciated colloid ?A. protein in waterB. Soap in waterC. Rubber in benzeneD. `FeCl_(3) " in " H_(2)O` |
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Answer» Correct Answer - b |
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| 1195. |
Which of the following are correctly matched?A. Butter-gelB. Milk-emulsionC. Fog-aerosolD. Dust-solid sol |
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Answer» Correct Answer - A::B::C |
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| 1196. |
Which of the following examples is correctly matched ?A. Butter-gelB. Smoke-emulsionC. Paint-foamD. Milk-aerosol |
| Answer» Correct Answer - A | |
| 1197. |
Which pair is correctly matched ?A. `[Fe(OH)_(3)] : Fe^(3+)`B. `[As_(2)S_(3)] : As^(3+)`C. `[SnO_(2)] : SnO_(3)^(2-)` in acidic mediumD. `[Agl] : I^(-)` in excess of `AgNO_(3)` |
| Answer» Correct Answer - A | |
| 1198. |
Which of the following is incorrect regarding Langmuir adsoroption isothem?A. Langmuir desived an adsorption isotherm on theoretical consideration based on kinetic theory of gases.B. Langmuir isotherm is based on the assumption that every adsorption site is equivalent and that the ability of a particle to bind there is independent of whether or not nearby sites are occupied.C. Langmuir considered adsorption to consist of the two opposing processes.D. The Langmuir isotherm is generally more successful in interpreting the data than the Freundlich isotherm when a multilayer is formed. |
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Answer» Correct Answer - D Langmuir assumed that the layer of the adsorbed gas was only one molecule thick i.e. unimolecular. Since such type of adsorption is obtained in the case of chemisorption. Langmuir adsorption isotherm works particularly well for chemisorption. The two opposing processes considered by Langmuir are (a) Adsorption of the gases molecules on the surface of the solid (b) Desorption of the adsorbed molecules from the surface of the solid. Langmuir believed that eventually a dynamic equilibrium is established between the above two opposing processes. |
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| 1199. |
Which forms multimolecular layer during adsorption?A. Physical adsorptionB. ChemisorptionsC. Both(a) and (b)D. none of these |
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Answer» Correct Answer - A Physical absorption forms multimolecular layer due to diffusion through pores and establishes weak force with solid. |
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| 1200. |
Which of the following are multimolecular colloids ?A. SulphurB. Egg albumin in waterC. Gold solD. Soap solution |
| Answer» Correct Answer - A::C | |