Download Jee 2014 Booklet6 Hwt Surface Chemistry PDF

TitleJee 2014 Booklet6 Hwt Surface Chemistry
Tags Applied And Interdisciplinary Physics Materials Chemical Substances Adsorption
File Size148.0 KB
Total Pages8
Document Text Contents
Page 1

Vidyamandir Classes

VMC/Surface Chemistry 25 HWT-6/Chemistry

DATE : TIME : 40 Minutes MARKS : [ ___ /15] TEST CODE : SRFC [1]

START TIME : END TIME : TIME TAKEN: PARENT’S SIGNATURE :

 This test contains a total of 15 Objective Type Questions. Each question carries 1 mark. There is NO NEGATIVE marking.

Choose the correct alternative. Only one choice is correct.

1. During the adsorption of krypton on activated charcoal at low temperature

(A) H 0 and S 0    (B) H 0 and S 0   

(C) H 0 and S 0    (D) H 0 and S 0   

2. Which of the following is a wrong statement for physisorption?
(A) It is a reversible reaction (B) Reaction requires an energy of activation
(C) The value of adsorption enthalpy is low (D) It generally occurs at a low temperature

3. Which of the following statements is incorrect regarding physisorptions?
(A) It occurs because of van der Waals’ forces
(B) More easily liquefiable gases are adsorbed readily
(C) Under high pressure it results into multimolecular layer on adsorbent surface

(D) Enthalpy of adsorption  adsorptionH is slow and positive

4. Freundlich equation for adsorption of gases (in amount of X g) on a solid (in amount of mg) at constant temperature can be
expressed as :

(A)
X 1

log log p log k
m n
  (B)

X 1
log log k log p

m n
 

(C) n
X

p
m
 (D)

X 1
log p log k

m n
 

5. From the following which is not a surface phenomenon?
(A) Corrosion (B) Crystallisation
(C) Heterogeneous catalysis (D) Water and its vapour in a closed vessel

6. Which of one of the following graphs represents Freundlich adsorption isotherm?

(A) (B) (C) (D)

7. Which of the following is not correct?
(A) Enthalpy of physical adsorption is less compared to enthalpy of chemical adsorption
(B) Milk is an example of emulsion
(C) Physical adsorption increases with the increase in temperature
(D) Smoke is an aerosol

8. Identify the correct statement for the adsorption of a real gas on charcoal at 1 atm and 15 C .

(A) Gases which are small in molecular size are adsorbed more
(B) Decrease in pressure increases the extent of adsorption
(C) Gases which are easily liquefiable are adsorbed more in quantity
(D) Gas which has a behaviour similar to an inert gas is adsorbed more

x
log

m

log p

x
log

m

log p

x
log

m

log p

x
log

m

log K

Page 2

Vidyamandir Classes

VMC/Surface Chemistry 26 HWT-6/Chemistry

9. Which one of the following characteristics is not correct for physical adsorption?
(A) Adsorption on solids is reversible
(B) Adsorption increases wit increases in temperature
(C) Adsorption is spontaneous
(D) Both enthalpy and entropy of adsorption are negative

10. Freundlich adsorption isotherm is

(A) 1/ n
x

kp
m
 (B) x = mkp1/n (C) nx / m kp (D) All of these

11. In Langmuir’s model of adsorption of a gas on a solid surface
(A) the rate of dissociation of adsorbed molecules from the surface does not depend on the surface covered
(B) the adsorption at a single site on the surface may involve multiple molecules at the same time
(C) the mass of gas striking a given area of surface is proportional to the pressure of the gas
(D) the mass of gas striking a given area of surface is independent of the pressure of the gas

12. Which of the following is true in respect of adsorption?

(A) G 0; S 0; H 0      (B) G 0; S 0; H 0     

(C) G 0; S 0; H 0      (D) G 0; S 0; H 0     

13. If (x/m) is the mass of adsorbate adsorbed per unit mass of adsorbent. p is the pressure of the adsorbate gas and a and b are
constants, which of the following represents “Langmuir adsorption isotherm”?

(A)
x a 1

log log log p
m b a
   

    
   

(B)
x b 1

m a ap
 

(C)
x 1 bp

m ap


 (D)

 
1 b 1

x / m a ap
 

14. The extent of adsorption of a gas on a solid depends on
(A) nature of the gas (B) pressure of the gas
(C) temperature of the gas (D) All of these

15. Which of the following is not a characteristic of chemisorptions?
(A) H is the order of 400 kJ (B) Adsorption is irreversible
(C) Adsorption may be mulitmolecular layer (D) Adorption is specific

Page 3

Vidyamandir Classes

VMC/Surface Chemistry 27 HWT-6/Chemistry

DATE : TIME : 25 Minutes MARKS : [ ___ /15] TEST CODE : SRFC [2]

START TIME : END TIME : TIME TAKEN: PARENT’S SIGNATURE :

 This test contains a total of 15 Objective Type Questions. Each question carries 1 mark. There is NO NEGATIVE marking.

Choose the correct alternative. Only one choice is correct.

1. Which is not correct regarding the adsorption of gas on surface of a solid?
(A) Enthalpy and entropy change is negative
(B) Adsorption is more for some specific substance
(C) On increasing temperature, adsorption increases progressively
(D) It is a reversible reaction

2. Which of the following is an example for homogeneous catalysis?
(A) Manufacture of sulphuric acid by Contact process
(B) Manufacture of ammonia by Haber’s process
(C) Hydrolysis for sucrose in presence of dilute hydrochloric acid
(D) Hydrogenation of oil

3. An example for autocatalysis is:
(A) oxidation of NO to NO2 (B) oxidation of SO2 to SO3
(C) decomposition of KClO3 to KCl and O2 (D) oxidation of oxalic acid by acidifed KMnO4

4. Statement 1 : A catalyst increases the rate of a reaction.
Statement 2 : In presence of a catalyst, the activation energy of the reaction increases.
The correct answer is :

5. Which reaction characteristics are changing by the addition of a catalyst to a reaction at constant temperature?
(i) Activation energy (ii) Equilibrium constant
(iii) Reaction entropy (iv) Reacton enthalpy
(A) (i) only (B) (iii) only (C) (i) and (ii) only (D) All of these

6. Associated colloid among the following is:
(A) enzymes (B) proteins (C) starch (D) sodium stearate

7. Which of the following electrolytes is least effective in coagulating ferric hydroxide solution?
(A) Cryolite (B) K2C2O4 (C) K3[Fe(CN)]6 (D) K4[Fe(CN)6]

8. Which of the following electrolytes is least effective in coagulating ferric hydroxide solution?
(A) KBr (B) K2SO4 (C) K2CrO4 (D) K4 [Fe (CN)6]

9. Which is the wrong pair?
(i) Starch solution : sol (ii) Aq. NaCl : true solution
(iii) milk : emulsion (iv) Aq. BaSO4 : true solution
(A) (i) (B) (iii) (C) (iv) (D) (ii)

10. Among the electrolytes Na2SO4, CaCl2, Al2 (SO4)3 and NH4Cl, the most effective coagulating agent for Sb2S3 sol is:
(A) Na2SO4 (B) CaCl2 (C) Al2 (SO4)3 (D) NH4Cl

Page 4

Vidyamandir Classes

VMC/Surface Chemistry 28 HWT-6/Chemistry

11. Which is more powerful to coagulate the negative colloid?
(A) ZnSO4 (B) Na3PO4 (C) AlCl3 (D) K4 [Fe (CN)6]

12. Select wrong statement.
(A) If very small amount of AlCl3 is added to gold sol, coagulation occurs, but if a large quantity of AlCl3 is added, there is

no coagulation
(B) Organic ions are more strongly adsorbed on charged surfaces in comparison to inorganic ions
(C) Both emulsifier and peptizing agents stabilize colloids but their action are different
(D) Colloidal solution are thermodynamically stable

13. The ion that is more effective for the coagulation of As2S3 sol is:

(A) Ba2+ (B) Na+ (C) 34PO
 (D) Al3+

14. Which one of the following impurities present in colloidal solution cannot be remove by electrodialysis?
(A) Sodium chloride (B) Potassium sulphate
(C) Urea (D) Calcium chloride

15. From the following which is not an emulsifier?
(A) Agar (B) Milk (C) Gum (D) Soap

Page 5

Vidyamandir Classes

VMC/Surface Chemistry 29 HWT-6/Chemistry

DATE : TIME : 25 Minutes MARKS : [ ___ /15] TEST CODE : SRFC [3]

START TIME : END TIME : TIME TAKEN: PARENT’S SIGNATURE :

 This test contains a total of 15 Objective Type Questions. Each question carries 1 mark. There is NO NEGATIVE marking.

Choose the correct alternative. Only one choice is correct.

1. Among the following, the surfactant that will form micelles in aqueous solution at the lowest molar concentration at ambient
conditions, is:

(A) 3 2 15 3 3CH (CH ) N (CH ) Br
  (B) 3 2 11 3CH (CH ) OSO Na

 

(C) 3 2 6CH (CH ) COO Na
  (D) 3 2 11 3 3CH (CH ) N (CH ) Br

 

2. Gold numbers of protective colloids A, B, C and D are 0.50, 0.01, 0.10 and 0.005, respectively. The correct order of their
protective powers is:
(A) D < A < C < B (B) C < B < D < A (C) A < C < B < D (D) B < D < A < C

3. Which one of the following is a lyophilic colloidal solution?
(A) Smoke (B) Gold sol
(C) Starch aqueous solution (D) Cloud

4. Which of the following is not a property of colloidal solution?
(A) Heterogenceity (B) Particle size > 100 nm
(C) Tyndall effect (D) Brownian movement

5. The basic principle of Cottrell’s precipitator is:
(A) Le-Chatelier’s principle (B) peptisation
(C) neutralisation of charge on colloidal particles (D) scattering of light

6. The colour of sky is due to :
(A) transmission of light (B) wavelength of scattered light
(C) absorption of light by atmospheric gases (D) All of the above

7. The number of moles of lead nitrate needed to coagulate 2 moles of colloidal [AgI]I is :

(A) 2 (B) 1 (C) 1/2 (D) 2/3

8. Which has least gold number?
(A) Gelatin (B) Starch (C) Albumin (D) Blood

9. The continuous phase contains the dispersed phase throughout, example is:
(A) water in milk (B) fat in milk
(C) water droplets in mist (D) oil in water

10. Which of the following electrolyte will have maximum flocculation vale of Fe (OH)3 sol?
(A) NaCl (B) Na2S (C) (NH4)3 PO4 (D) K2SO4

11. Bleeding due to a cut can be stopped by applying ferric chloride solution in the laboratory. This is due to
(A) coagulation of negatively charged blood particles by Fe3+ ions

(B) coagulation of positively charged blood particles by Cl ions

(C) reaction taking place between ferric ions and the haemoglobin forming a complex
(D) common element, iron, in both FeCl3 and haemoglobin

Page 6

Vidyamandir Classes

VMC/Surface Chemistry 30 HWT-6/Chemistry

12. When a sulphur sol is evaporated sulphur is obtained. On mixing with water sulphur sol is not formed. The sol is:
(A) lyophilic (B) reversible (C) hydrophobic (D) hydrophilic

13. On adding 1 mL of solution of 10% NaCl to 10 mL of gold sol in the presence of 0.25 g of starch, the coagulation is just
prevented. The gold number of starch is:
(A) 0.25 (B) 0.025 (C) 2.5 (D) 250

14. Which of the following is not correct?
(A) Milk is a naturally occurring emulsion
(B) Gold sol is a lyophilic sol
(C) Physical adsorption decreases with rise in temperature
(D) Chemical adsorption is unilayered

15. Which of the following has maximum value of flocculating power?
(A) Pb2+ (B) Pb4+ (C) Sr2+ (D) Na+

Page 7

Vidyamandir Classes

VMC/Surface Chemistry 31 HWT-6/Chemistry

DATE : TIME : 40 Minutes MARKS : [ ___ /15] TEST CODE : SRFC [4]

START TIME : END TIME : TIME TAKEN: PARENT’S SIGNATURE :

 This test contains a total of 15 Objective Type Questions. Each question carries 1 mark. There is NO NEGATIVE marking.

Choose the correct alternative. Only one choice is correct.

1. Blue colour of water in sea is due to :
(A) Refraction of blue light by impurities (B) Refraction of blue sky by water
(C) Scattering of light by water (D) None of the above

2. When dilute aqueous solution of AgNO3 (excess) is added to KI solution, positively charged sol of AgI is formed due to adsorption
of

(A) 3NO
 (B) 2O

 (C) Ag+ (D) K+

3. Which of the following will be the mot effective in the coagulation of Fe (OH)3 sol?
(A) KCN (B) BaCl2 (C) NaCl (D) Mg3 (PO4)2

4. The gold numbers of some colloidal solutions are given below:

The protective nature of these colloidal solutions follow the order :
(A) C > B > A (B) A > B > C (C) A = B = C (D) B > A > C

5. Lyophilic sols are :
(A) irreversible sols (B) they are prepared from inorganic compounds
(C) coagulated by adding electrolytes (D) self-stabilising

6. The volume of a colloidal particle, VC as compared to the volume of a solute particle in a true solution VS, could be:

(A) 3C
S

V
10

V
 (B) 3C

S

V
10

V
 (C) 23C

S

V
10

V
 (D) C

S

V
1

V


7. The disperse phase in colloidal iron (III) hydroxide and colloidal gold is positively and negatively charged, respectively. Which of
the following statements is not correct?
(A) Coagulation in both sols can be brought about by electrophoresis
(B) Mixing the sols has no effect
(C) Sodium sulphate solution causes coagulation in both sols
(D) Magnesium chloride solution coagulates the gold sol more readily than the iron (III) hydroxide sol

8. Pick out the statement which is not relevant in the discussion of colloids.
(A) Sodium aluminium silicate is used in the softening of hard water
(B) Potash alum is used in shaving rounds and as a styptic in medicine
(C) Artificial rain is caused by throwing electrified sand on the clouds from an aeroplane
(D) Deltas are formed at a place where the river pours its water into the sea

9. On addition of 1 mL solution of 10% NaCl to 10 mL gold solution in the presence of 0.025 g of starch, the coagulation is
prevented because starch has the following gold numbers
(A) 25 (B) 0.025 (C) 0.25 (D) 2.5

Colloidal solution Gold number

A 0.01

B 2.5

C 20

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