The addition of alcohol to a saturated aqueous solution fo calucium acetate first forms a sol and them sets to a gelatinous mas scalled solid alcohnlo ehich is a:

The addition of alcohol to a saturated aqueous solution of calcium acetate first forms a sol and then sets to a gelatinous mass called solid alcohol which is a

On addition of aqueous NaOH to a salt solution, a white gelatinous precipitate is formed, which dissolves in excess of alkali. The salt solution contains

A unknown inorganic compound (X) gave the following reactions : (i) on heating 'X' gave a residue, oxygen and oxide of nitrogen. (ii) Addition of acetic acid and K_(2)Cr_(2)O_(7) to its aqueous solution give a yellow precipitate. (iii) Addition of NaOH to its aqueous solution first forms a white precipitate, dissolve in the excess of the reagent. Identify the compound (X) and write balanced equation for step (i),(ii), & (iii).

If a springly soluble salt is placed in water, after some time an equilibrium is established when the rate of dissolution of ions form the soid equal to the rate of precipitation of ions from the saturated solution at a particular temperature. Thus, a dynamic equilibrium exists between the undissociated solid species and the dissolved ionic species in a saturated and the dissolved ionic species in a saturated solution at a particular temperature. For example, in AgCl , we have the following equilibrium: AgCl_((aq.)) Ag_((aq))^(+) + Cl_((aq))^(-) The equilibrium constant K_(eq) = ([Ag^(+)][Cl^(-)])/([AgCl]) K_(eq) xx [AgCl] = [Ag^(+)] [Cl^(-)] rArr K_(sp) (AgCl) = [Ag^(+)][Cl^(-)]"........"(A)" :' [AgCl] is constant If there would not have been a saturated solution, then from equation (A), Keq. [AgCl] ne K_(sp) , but K_(eq).[AgCl] = Q_(AgCl) , where Q is ionic product, it implies that for a saturated solution, Q = K_(sp) K_(sp) is temperature dependent. When Q lt K_(sp) , then the solution is unsaturated and there will be no precipitate formation. When Q = K_(sp) , then solution will be saturated, no and ppt. will be formed When Q gt K_(sp) , the solution will be supersaturated and there will be formation precipitate. The solubility product of ferric hydroxide in aqueous solution is 6 xx 10^(-38) at 298 K . The solubility of Fe^(3+) ions will increase when the :

Following passage describes charcterstics of colloids. Answer the questions at the end of it. Lyophilic colloidal sols are much more stable than lyophobic colloidal sols. This is due to the extensive solvation of lyophilic colloidal sols, which forms a protective layer outside it and thus prevents it from forming associated colloids. Lyophillic colloidal sols also protect lyophobic colloidal sols from precipition by the action of electrolytes. This is due to formation of a protective layer by lyophilic sols outside lyophobic sols. Lyophilic colloidal sols are called protective sols. Gelatin (lyophilic) protects gold sol (lyophobic) from coagulaion on the addition of sodium chloride solution. Protective powers of different colloidal sols are measured in terms of 'gold number' (Zigmody). It is defined as the amount of protective sol in milligrams that prevents the coagulation of 10 mL of a given gold sol on adding 1 mL of 10 percent sodium chloride. Thus smaller the gold number of a lyophillic sol, the greater is the protective power. 0.025g of starch sol is required to prevent coagulation of 10ml gold sol when ImL of 10% Nacl solution is present. What is gold number of starch sol