Tiêu đề DPP-6 SOLUTION.pdf ✅

CLASS : XIth SUBJECT : CHEMISTRY DATE : DPP No. : 6 1 (d) These are different forms of Freundlich equation. 2 (c) Initially Pt asbestos was used. Now-a-days a relatively cheaper catalyst V2O5 is used. Also it is not poisoned by CO and As2O3. 3 (b) Adsorbent is the surface on which adsorption occurs 4 (c) In Cottrell’s precipitator, the charged particles are attracted towards the walls of precipitator, here they lose their charge and coagulate. Hence, the basic principle of Cottrell’s precipitator is the neutralisation of charge on colloidal particles. 5 (d) Freundlich adsorption isotherm gives relationship between pressure and amount of substrate adsorbed. x/m = kp 1 n (where, x/m = amount adsorbed ,p = pressure) or x = m.kp 1 n or x/m = kp ―n ∴ All equations represent Freundlich adsorption isotherm. 6 (c) Butter is an w/o emulsion having fat dispersed in water. 7 (b) Peptisation is a process in which freshly prepared precipitate disintegrates into colloidal solution 8 (a) A negative catalyst is one which lowers the rate of chemical reaction. eg, Addition of chloroform to H2O2 prevents the decomposition of CHCl3 to a great extent 9 (a) Gold no.is the amount of lyophilic in mg which just protect 10 mL gold sol against coagulation by 1 mL of 10% NaCl solution. It is a measure of protective power of lyophilic colloids. Topic :- SURFACE CHEMISTRY Solutions