Tiêu đề 05. SURFACE CHEMISTRY.pdf ✅

PAPER 1 (1.) The right option for the statement "Tyndall effect is exhibited by", is: [NEET 2021] (1) Starch solution (2) NaCl solution (3) Urea solution (4) Glucosesolution (2.) The incorrect statement regarding enzymes is (1) Enzymes are very specific for a particular reaction and substrate. (2) Enzymes are biocatalysts. (3) Like chemical catalysts enzymes reduce the activation energy of bio processes. (4) Enzymes are polysaccharides. (3.) Given below are two statements Statement I: In the coagulation of a negative sol, the flocculating power of the three given ions is in the order 3 2 Al Ba Na + + +   Statement II: In the coagulation of a positive sol, the flocculating power of the three given salts is in the order NaCl Na SO Na PO 2 4 3 4   In the light of the above statements, choose the most appropriate answer from the options given below (1) Statement I is incorrect but Statement II is correct. (2) Both Statement I and Statement II are correct. (3) Both Statement I and Statement II are incorrect. (4) Statement I is correct but Statement II is incorrect. (4.) Which of the following is a positively charged sol? [NEET 2023 MANIPUR] (1) Methylene blue sol (2) Congo red sol (3) Silver sol (4) Sb S2 3 sol (5.) Which one is an example of heterogeneous catalysis? [NEET 2023] (1) Decomposition of ozone in presence of nitrogen monoxide. (2) Combination between dinitrogen and dihydrogen to form ammonia in the presence of finely divided iron. (3) Oxidation of sulphur dioxide into sulphur trioxide in the presence of oxides of nitrogen. (4) Hydrolysis of sugar catalysed by H + ions. (6.) Pumice stone is an example of [NEET 2023] (1) solid sol (2) foam (3) sol (4) gel.
(7.) When animal charcoal is added to a solution of methylene blue, it was observed that the filtrate tums colorless. The reason for this is [Page: 124] (1) absorption (2) adsorption (3) sorption (4) desorption. (8.) A solid acts as on adsorbent because it has [Page: 124] (1) high lattice energy (2) small pores in it (3) definite shape & volume (4) unsaturated valencies. (9.) In the adsorption of sugar on activated charcoal, sugar and charcoal are respectively [Page: 124] (1) adsorbate, adsorbent (2) adsorbate, adsorber (3) adsorber, absorber (4) adsorbent, adsorbate (10.) Which of the following is not an example of absorption? [NCERT Exemplar Modified, Page: 124] (I) Water on silica gel (II) Water on calcium chloride (III) Hydrogen on finely divided nickel (IV) Oxygen on metal surface (1) I & II only (2) I a III only (3) II only (4) I, III & IV only (11.) The term sorption includes [NCERT Exemplar Modified, Page: 124] (1) absorption (2) adsorption (3) both absorption a adsorption (4) adsorption followed by desorption. (12.) During the adsorption of a gas on the surface of a solid, which of the following is true? [Page: 125] (1)       G 0, H 0, S 0 (2)       G 0, H 0, S 0 (3)       G 0, H 0, S 0 (4)       G 0, H 0, S 0 (13.) Read the given statements [Page: 125] (I) Adsorption increases with increase in temperature. (II) Adsorption is spontaneous. (III) Both enthalpy and entropy of adsorption are entropy. (IV) Adsorption on solids is reversible Which of the given statements is/are correct about adsorption? (1) II, III & IV (2) I only (3) II & III (4) III & IV (14.) Why do physisorption and chemisorption behave differently with increasing temperature [Page: 125] (1) Physisorption forms multilayers while chemisorption form unimolecular (2) Physisorption is not specific while chemisorption is highly specific in nature.