Tiêu đề DPP-4 SOLUTION.pdf ✅

CLASS : XIth SUBJECT : CHEMISTRY DATE : DPP No. : 4 1 (d) The action of enzyme in living system is to enhance the rate of biochemical reactions. 3 (b) Catalyst shows exothermic adsorption of reactant molecules and thus, energy of activation is lowered. 5 (d) In a, b, c anionic micelle is formed. 6 (c) Colloidal solution is prepared by electrical dispersion, peptization and mechanical dispersion. It is not prepared by coagulation because coagulation is the phenomenon of the precipitation of colloidal solution by the addition of the electrolyte. 7 (d) Volume of the gold dispersed in one litre water = mass density = 1.9 × 10―4 g 19g cm―3 = 1 × 10―5 cm―3 Radius of gold sol particle =10 nm = 10 × 10―9m = 10 × 10―7 cm Volume of the gold sol particle = 4 3 πr 3 = 4 3 × 22 7 × (10―6 ) 3 = 4.19 × 10―18cm3 Number of gold sol particle in 1 × 10―5 cm3 = 1 × 10―5 4.19 × 10―18 = 2.38 × 1012 Number of gold sol particle in one mm3 = 2.38 × 1012 106 Topic :- SURFACE CHEMISTRY Solutions
= 2.38 × 106 9 (a) Usually poisons for human body are poison for catalysts. 10 (b) If reactant + catalyst have P = 1 then homogeneous catalysis. 11 (c) The reaction in solution phase (P = 1) is catalysed by H + . 12 (c) Such a process involving oxidation of one substance in presence of other which would otherwise not been possible is called induced catalysis or better to say induced oxidation. 13 (c) Detergents possess surface activity like surfactants as well as cleaning action. 14 (d) When dispersed phase is gas and dispersion medium is solid the colloidal sol obtained is termed as solid foam 15 (a) Lower is the value of gold number, more is its protecting power. 16 (d) Due to dipole and van der Waals’ forces of attraction. 17 (c) Polyoxyethylene glycols and their derivatives are non-ionic detergents. 18 (a) Graph (a) represent correctly the action of catalysis 19 (d) Colloidal solution of CuCl2 is not prepared by double decomposition method 20 (c) Hydrogenation of oils requires Ni as catalyst.
ANSWER-KEY Q. 1 2 3 4 5 6 7 8 9 10 A. D D B D D C D D A B Q. 11 12 13 14 15 16 17 18 19 20 A. C C C D A D C A D C