Surface Chemistry PYQs Set 7 (PDF)

Set 7 of 8 · Questions 181-210 of 227

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Mere Teacher · Previous Year Questions NEET Chemistry · Surface Chemistry · Set 7 (Q181-210)
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181. $Milk-water mixture when viewed by the reflected light appears in which colour?$ (1) $Yellow$ (2) $Green$ (3) $Blue$ (4) $Red$ 182. $Dalda is prepared from oils by$ (1) $hydrolysis$ (2) $distillation$ (3) $oxidation$ (4) $reduction.$ 183. $Which of the following statements is incorrect w.r.t. physisorption?$ (1) $The forces involved are van der Waals' forces.$ (2) $More easily liquifiable gases are adsorbed easily.$ (3) $Under high pressure it results into multi-molecular layer on adsorbent surface.$ (4) $Δ H_{adsorption} is low and +ve.$ 184. $A sample of red ink (a colloidal suspension) is prepared by mixing eosin dye, egg white, HCHO and water. The component which ensures stability of the ink sample is:$ (1) $HCHO$ (2) $Water$ (3) $Eosin dye$ (4) $Egg white$ 185. $Gold numbers of some colloids are: Gelatin: 0.005 - 0.01, Gum Arabic: 0.15 - 0.25 ; Oleate: 0.04 - 1.0; Starch : 15 - 25. Which among these is a better protective colloid?$ (1) $Gelatin$ (2) $Starch$ (3) $Gum Arabic$ (4) $Oleate$ 186. $Gold numbers of protective colloids A, B, C and D are 0.50, 0.01, 0.10 and 0.005, respectively. The correct order of their protective powers is$ (1) $C < B < D < A$ (2) $A < C < B < D$ (3) $B < D < A < C$ (4) $D < A < C < B$ 187. $Among the colloids cheese (c), milk (M) and smoke (S), the correct combination of the dispered phase and dispersion medium, respectively is :$ (1) $C : liquid in solid; M : liquid in liquid; S : solid in gas$ (2) $C : solid in liquid; M : liquid in liquid; S : gas in solid$ (3) $C : solid in liquid; M : solid in liquid; S : solid in gas$ (4) $C : liquid in solid; M : liquid in solid; S : solid in gas$ 188. $The disperse phase in colloidal iron (III) hydroxide and colloidal gold is positively and negatively charged, respectively. Which of the following statements is NOT correct?$ (1) $Coagulation in both sols can be brought about by electrophoresis$ (2) $Mixing the sols has no effect$ (3) $Sodium sulphate solution causes coagulation in both sols$ (4) $Magnesium chloride solution coagulates, the gold sol more readily than the iron (III) hydroxide sol.$ 189. $Tyndall effect is more effectively shown by:$ (1) $true solution$ (2) $lyophilic colloid$ (3) $lyophobic colloid$ (4) $suspension$ 190. $Which one of the following is not a property of physical adsorption?$ (1) $Higher the pressure, more the adsorption$ (2) $Greater the surface area, more the adsorption$ (3) $Lower the temperature, more the adsorption$ (4) $Unilayer adsorption occurs$ 191. $Photographic plates are prepared by coating emulsion of which of the following in gelatin.$ (1) $AgBr$ (2) $CuBr$ (3) $ZnB_{2}$ (4) $FeBr_{2}$ 192. $Among the following, correct statement is:$ (1) $One would expect charcoal to adsorb chlorine more than hydrogen sulphide$ (2) $Sols metal sulphides are lyophilic$ (3) $Hardy Schulze law states that bigger the size of the ions, the greater is its coagulating power.$ (4) $Brownian movement is more pronounced for smaller particles than for bigger-particles.$ 193. $In Freundlich adsorption isotherm, the value of 1 l n is$ (1) $between 0 and 1 in all cases$ (2) $between 2 and 4 in all cases$ (3) $1 in case of physical absorption$ (4) $1 in case of chemisorption.$ 194. $For the adsorption of a gas on a solid, the plot of versus l o g P is linear with slope equal to$ (1) $n$ (2) $1 l n$ (3) $k$ (4) $l o g k .$ 195. $Among the following the number of curves not in accordance with Freundlich adsorption isotherm is$ (1) (2) (3) (4) 196. $Kraft temperature is the temperature$ (1) $below which the aqueous solution of detergents starts freezing.$ (2) $above which the formation of micelles takes place.$ (3) $below which the formation of micelles takes place.$ (4) $above which the aqueous solution of detergents starts boiling.$ 197. $A plot of lo g (x / m) versus lo g p for the adsorption of a gas on a solid gives a straight line with slope equal to$ (1) $l o g K$ (2) $- l o g K$ (3) $n$ (4) $\frac{1}{n}$ 198. $Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R. Assertion A : Finest gold is red in colour, as the size of the particles increases, it appears purple then blue and finally gold. Reason R : The colour of the colloidal solution depends on the wavelength of light scattered by the dispersed particles. choose the most appropriate answer from the options given below:$ (1) $Both A and R are true and R is the correct explanation of A$ (2) $Both A and R are true but R is NOT the correct explanation of A$ (3) $A is true but R is false$ (4) $A is false but R is true$ 199. $Which one of the following is an example for homogeneous catalysis?$ (1) $Manufacture of sulphuric acid by contact process$ (2) $Manufacture of ammonia by Haber's process$ (3) $Hydrolysis of sucrose in presence of dilute hydrochloric acid$ (4) $Hydrogenation of oil$ 200. $If x is amount of adsorbate and m is amount of adsorbent, which of the following relations is not related to adsorption process?$ (1) $x l m = f_{(} p_{)} at constant T$ (2) $x l m = f_{(} T_{)} at constant p$ (3) $p = f_{(} T_{)} at constant$ (4) $\frac{x}{m} = p \times T$ 201. $Among the following, the false statement is:$ (1) $It is possible to cause artificial rain by throwing electrified sand carrying charge opposite to the one on clouds from an aeroplane.$ (2) $Lyophilic solution can be coagulated by adding an electrolyte$ (3) $Latex is a colloidal solution of rubber particles which are positively charged$ (4) $Tyndall effect can be used to distinguish between a colloidal solution and a true solution$ 202. $Which of the following is true for spontaneous adsorption of H_{2} gas without dissociation on solid surface$ (1) $Process is exothermic and Δ S < 0$ (2) $Process is endothermic and Δ S > 0$ (3) $Process is exothermic and Δ S > 0$ (4) $Process is endothermic and Δ S < 0$ 203. $The protecting power of lyophilic colloidal sol is expressed in terms of$ (1) $coagulation value$ (2) $gold number$ (3) $critical micelle concentration$ (4) $oxidation number.$ 204. $Relatively which conditions favour the faster Brownian movement of colloidal particles in solution?$ (1) $Smaller size and higher viscosity$ (2) $Smaller size and lesser viscosity$ (3) $Bigger size and higher viscosity$ (4) $Bigger size and lesser viscosity$ 205. $An example for hydrophobic sol among the following is \dots\dots...$ (1) $gum solution$ (2) $arsenic sulphide solution$ (3) $starch solution$ (4) $protein solution$ 206. $The sol given below with negatively charged colloidal particles is :$ (1) $F e C l_{3} added to hot water$ (2) $KIadded to A g N O_{3} solution$ (3) $A g N O_{3} added to KI solution$ (4) $A l_{2} O_{3} \cdot x H_{2} O in water$ 207. $The process which is responsible for the formation of delta at a place where rivers meet the sea is$ (1) $peptization$ (2) $colloidal formation$ (3) $emulsification$ (4) $coagulation.$ 208. $Which one of the following is not an emulsion?$ (1) $Milk$ (2) $Soap lather$ (3) $Butter$ (4) $Vanishing cream$ 209. $For Freundlich adsorption isotherm, a graph of log (x / m) us. log (P) gives a straight line. The slope of line and its Y -axis intercept respectively are$ (1) $log (\frac{1}{n}), K$ (2) $\frac{1}{n}, log K$ (3) $log (\frac{1}{n}), log K$ (4) $\frac{1}{n}, K$ 210. $The process in which colloids, when subjected to DC electric field move towards an electrode is$ (1) $Brownian movement$ (2) $Tyndall effect$ (3) $Peptization$ (4) $Electrophoresis$