Chemistry NCERT Exemplar Solutions Class 12th Chapter Five

For ideal gas using ;

PM = dRT

$P=\left(\frac{RT}{M}\right)d$

Comparing with y = mx + C

Slope, m =  $\frac{RT}{M}$

Slope $\propto$  T

So; higher the slope higher the T

Hence, T₃ > T₂ > T₁

Using, Freundlich adsorption isotherm ;

$\frac{x}{m}=k.p^{1/n}$       ………………. (i)

$log\frac{x}{m}=\frac{1}{n}logp+logk$                

Comparing with y = mx + C

Slope = $\frac{1}{n}$  = 1

Intercept, log k = 0.602

log k = log 4

k = 4

from equation (i)

  $\frac{x}{m}=4*{\left(0.03\right)}^1$              

= 0.12

= 12 * 10^-2

So, 12 * 10^-2 g of gas is adsorbed per gram of adsorbent,

This is a Assertion and Reason Type Questions as classified in NCERT Exemplar

Ans: Detergents with low CMC are more economical to use as they involve formation of micelle which is used for cleaning of oil and dirt from our cloth. Micelle formation takes place when the concentration of the detergent becomes equal to the CMC so the answer is (i).

This is a Assertion and Reason Type Questions as classified in NCERT Exemplar

Ans: Greater the valence of the flocculating ion added, the greater is its power to cause precipitation. This is known as Hardy schulze rule. In the coagulation of a negative sol, the flocculating

This is a Assertion and Reason Type Questions as classified in NCERT Exemplar

Ans: Colloidal particle shows Brownian movement. The Brownian movement has a stirring effect which does not permit the particles to settle and thus, is responsible for the stability of sols so the answer is (v).

This is a Assertion and Reason Type Questions as classified in NCERT Exemplar

Ans: Colloidal particles being bigger aggregates, the number of particles in a colloidal solution is comparatively small as compared to a true solution. Hence, the values of colligative properties (osmotic pressure, lowering in vapour pressure, depression in freezing point and elevation in boiling point) are of small order as compared to values shown by true solutions at same concentration hence the answer is (i).

This is a Assertion and Reason Type Questions as classified in NCERT Exemplar

Ans: Colloidal particles can pass through ordinary filter paper because the pores are too large. However, the pores of filter paper can be reduced in size by impregnating with collodion solution to stop the flow of colloidal particles hence the answer is (iii).

This is a Matching Type Questions as classified in NCERT Exemplar

Ans: The answers are: (i)- (d) (ii)- (c) (iii)- (a) (iv)- (b)