Title DPP-3 SOLUTION.pdf ✅

CLASS : XIth SUBJECT : CHEMISTRY DATE : DPP No. : 3 1 (b) k = Ae ―Ea/RT; higher is Ea, lesser is k. 2 (b) Oils + H2 (Unsaturated) Ni Ghee (Saturated) 3 (c) 2H2O2(l) Pt (s) 2H2O(l) + O2(g) In this reaction, reactants and catalyst are in different phase, hence it is an example of heterogeneous catalysis. 4 (a) Palmitate is an anion and not a macromolecule. 6 (b) Soap solutions act as emulsifier to remove grease via emulsification of grease in water. 7 (d) All the option are correct for Freundlich adsorption isotherm at different pressures. x m = kp 1 (at low pressure) x m = kp 0 (at high pressure) x m = kp 1/n (at intermediate pressure) 8 (d) Adsorption is an exothermic process i.e., energy is released against van der Waals’ force of attraction (physisorptions). Hence, ∆H is always negative. 9 (b) The catalysts used are CuCl2 in Deacon’s process, NO in chamber process and Fe in Haber’s process. 10 (c) Enzymes are biological catalysts produced by living cells which catalyze the biochemical reactions in living organisms. Hydrolysis of urea by urease (enzyme) is an example of biochemical catalysis. Topic :- SURFACE CHEMISTRY Solutions
11 (d) Equation, SO2(g) + 1 2 O2(g) V2O5(l) SO3(g) is only example of heterogeneous catalysis 12 (a) Milk is an emulsion in which the particles (or globules) of liquid fats are dispersed in water. 13 (a) Protective power of colloid ∝ 1 gold number ∴ Gelatin has lowest gold number among given choices. ∴ Gelatin is best protective colloid. 14 (b) 2HNO3 + 3H2S→3S + H2O + 2NO This equation is used for the preparation of sulphur sol 15 (d) Each one brings in neutralization of charges on sol particles. 16 (b) 2SO2(g) + O2(g) Pt(s) 2SO3; Phase for reactant + catalyst = 2; Thus, heterogeneous. 17 (a) Negatively charged sols require minimum amount of electrolyte having higher valence of cation. 18 (c) The dispersed phase particles bear continuous collisions with dispersion medium to show irregular motion in sol state. 19 (a) Freundlich adsorption isotherm is given as x m = kp 1/n(at a particular pressure) When x = 1, x m = kp (at low pressure) When n > 1, x m = k(at high pressure) 20 (d) Autocatalysis is a process in which one of the product behaves as a catalyst. e.g.,2KMnO4 + 5H2C2O4 + 3H2SO4→K2SO4 + 2MnSO4 + 8H2O + 10CO2
(acts as catalyst) The pink colour of KMnO4dissappears slowly on reaction with oxalic acid, but the rate of disappearance of colour fastens after sometime due to the formation of MnSO4 which acts as autocatalyst for the reaction.
ANSWER-KEY Q. 1 2 3 4 5 6 7 8 9 10 A. B B C A B B D D B C Q. 11 12 13 14 15 16 17 18 19 20 A. D A A B D B A C A D