Q: Adsorption of phenol from its aqueous solution on to fly ash obeys Freundlich isotherm. At a given temperature, from 10 mg g ^ -1 and 16 mg g ^ -1 aqueous phenol solutions, the concentrations of adsor

aligned & x m =K C^ 1 / n \\ & ( x m )= K+ 1 n C \\ & 4= K+ 1 n 10 \\ & 0.6= K+ 1 n .....(1) \\ & 10= K+ 1 n 16 \\ & 1= K+ 1 n 1.2 ....(2) aligned Equation (2) - equation (1) 0.4= 1 n (0.2) n =0.5 and K =-1.4 aligned & x m = K+ 1 n C \\ & =-1.4+2 20 aligned aligned & =-1.4+2.6=1.2 \\ & x m =10^ +1.2 =16 \\ & ( 2=0.3,4 2=1.2,16=10^ +1.2 ) aligned aligned & x m =K C^ 1 / n \\ & 4=K(10)^ 1 / n ....(1) \\ & 10=K(16)^ 1 / n ....(2) \\ & X=K(20)^ 1 / n ....(3) aligned On solving equation (1) and (2) 1

Question 1

At a given temperature, 0.45 g of acetic acid in 50 mL of water is shaken with 1.0 g of charcoal and the pH of the resulting solution is 3.0. Assume, the adsorption of acetic acid from the aqueous sol

Accepted Answer

Given the pH of the resulting solution is 3.0, the concentration of H^+ ions is: [H^+] = 10^ -3 M For the dissociation of acetic acid (CH_3COOH CH_3COO^- + H^+), the acid dissociation constant is given by: K_a = [CH_3COO^-][H^+] [CH_3COOH] Assuming [CH_3COO^-] [H^+] and the equilibrium concentration of acetic acid is C, we can use the approximation: K_a = [H^+]^2 C 1.0 10^ -5 = (10^ -3 )^2 C C = 10^ -6 1.0 10^ -5 = 0.1 M The number of moles of acetic acid remaining in the 50 mL (0.05 L ) solutio

Question 2

Adsorption of phenol from its aqueous solution on to fly ash obeys Freundlich isotherm. At a given temperature, from 10 mg g ^ -1 and 16 mg g ^ -1 aqueous phenol solutions, the concentrations of adsor

Accepted Answer

aligned & x m =K C^ 1 / n \ & ( x m )= K+ 1 n C \ & 4= K+ 1 n 10 \ & 0.6= K+ 1 n .....(1) \ & 10= K+ 1 n 16 \ & 1= K+ 1 n 1.2 ....(2) aligned Equation (2) - equation (1) 0.4= 1 n (0.2) n =0.5 and K =-1.4 aligned & x m = K+ 1 n C \ & =-1.4+2 20 aligned aligned & =-1.4+2.6=1.2 \ & x m =10^ +1.2 =16 \ & ( 2=0.3,4 2=1.2,16=10^ +1.2 ) aligned aligned & x m =K C^ 1 / n \ & 4=K(10)^ 1 / n ....(1) \ & 10=K(16)^ 1 / n ....(2) \ & X=K(20)^ 1 / n ....(3) aligned On solving equation (1) and (2) 1

Question 3

Consider the following statements related to colloids. (I) Lyophobic colloids are not formed by simple mixing of dispersed phase and dispersion medium. (II) For emulsions, both the dispersed phase and

Accepted Answer

As in Lyophobic colloids there is no interaction between dispersed phase and dispersion medium, special methods are used for preparation, simple mixing will not form colloid. Emulsion are colloids of liquid dispersed phase and liquid dispersion medium. Micelles formation occurs when temperature is above a particular temperature called Kraft temperature T K  and concentration above a particular value know as critical micelle concentration (CMC). Tyndall's effect can be observed when the

Question 4

The correct option(s) related to adsorption processes is(are)

Accepted Answer

(A) First statement is correct as chemisorption results in a unimolecular layer and physisorption result in a multimolecular layer. (B) Second statement is incorrect as enthalpy change during physisorption is of the range of 20 - 40 kJmol - 1 .Gases with higher critical temperatures are readily adsorbed (C) Chemisorption is an exothermic process with 80 - 240 kJmol - 1 as the enthalpy of adsorption. (D) Lowering the temperature results in increase in the extent of physisorption.It decreases

Question 5

The correct statement  s related to colloids is(are)

Accepted Answer

The process of setting of colloidal particles by adding electrolyte is called coagulation or precipitation of the sol. Peptization is the process of converting a precipitate into colloidal sol by shaking it in a medium in presence of a small amount of electrolyte. Colloidal solution have a lower value of colligative properly so, their depression in freezing point will be low, and freezing point will be higher. Surfactants form micelle above C.M.C and value of CMC depends on temperature

Question 6

Molar conductivity &#8896; m &#160; of aqueous solution of sodium stearate, which behaves as a strong electrolyte, is recorded at varying concentration(c) of sodium stearate. Which one of the followin

Accepted Answer

With increase in concentration of sodium stearate λ M decreases, but at CNC, formation of miceller take place and the λ M decrease abruptly, this change in λ M with respect to c is represented by plot.

Surface Chemistry — Previous Year Questions & Solutions