CBSE Class 12 Chemistry Surface Chemistry Worksheet Set 03

Question. At the critical micelle concentration, the surfactant molecules:
a. Decompose
b. Dissociate
c. Associate
d. Become completely soluble
Answer : C

Question. Sky looks blue due to:
a. Dispersion effect
b. Reflection
c. Transmission
d. Scattering
Answer : D

Question. Which of the following electrolytes is least effective in causing flocculation of ferric hydroxide sol?
a. K₄[Fe(CN)₆]
b. K₂CrO₄
c. KBr
d. K₂SO₄
Answer : C

Question. Which of the following is true about catalyst?
a. It initiates reaction
b. It changes equilibrium point
c. It increase average kinetic energy
d. It accelerates the rate of reaction
Answer : D

Question. Which of the following substances gives a positively charged sol?
a. Gold
b. A metal sulphite
c. Ferric hydroxide
d. An acidic dye
Answer : C

Question. Which of the following electrolytes have maximum coagulating power?
a. CCl₄
b. ZnCl₂
c. KCl
d. NaCl
Answer : B

Question. The decomposition of H₂O₂ can be slowed down by the addition of small amount of phosphoric acid which act as:
a. Promoter
b. Inhibitor
c. Detainer
d. Stopper
Answer : B

Question. A liquid aerosol is a colloidal system of:
a. A liquid dispersed in a solid
b. A liquid dispersed in a gas
c. A gas dispersed in a liquid
d. A solid dispersed in a gas
Answer : B

Question. If the dispersed phase is a liquid and the dispersion medium is a solid, the colloid is known as:
a. A sol
b. An emulsion
c. A gel
d. A foam
Answer : C

Question. On addition of one ml solution of 10% NaCl to 10 ml gold sol in the presence of 0.25 gm of starch, the coagulation is just prevented. Starch has the following gold number:
a. 0.025
b. 0.25
c. 0.5
d. 250
Answer : D

Question. Ferric hydroxide sol is positively charged colloid. The coagulating power of NO₃⁻ ,SO₄²⁻ and PO₄³⁻ ions would be in the order:
a. NO₃⁻ > SO₄²⁻ > PO₄³⁻
b. SO₄²⁻ > NO₃⁻ > PO₄³⁻
c. PO₄³⁻ > SO₄²⁻ > NO₃⁻
d. NO₃⁻ = SO₄³⁻ = PO₄³⁻
Answer : C

Question. The stability of lyophilic colloids is due to:
a. Charge on their particles
b. A layer of dispersion medium on their particles
c. The smaller size of their particles
d. The large size of their particles
Answer : B

Question. Size of colloidal particles varies from:
a. 10⁻⁷ to 10⁻⁹
b. 10⁻⁹ to 10⁻¹⁷
c. 10⁻⁵ to 10⁻⁷
d. 10⁻⁴ to 10⁻¹⁰ 
Answer : A

Question. When a substance comes in colloidal state the surface area of the particles?
a. Increases
b. Decreases
c. Remains unchanged
d. First increases then decreases
Answer : A

Question. Which of the following molecules is most suitable to disperse benzene in water?

Answer : C

Question. As₂S₃ sol has a negative charge. Capacity to precipitate it is highest in:
a. AlCl₃
b. Na₃PO₄
c. CaCl₂
d. K₂SO₄
Answer : A

Question. When dispersed phase is liquid and dispersion medium is gas, then the colloidal system is called?
a. Smoke
b. Clouds
c. Emulsion
d. Jellies
Answer : B

Question. Milk can be preserved by adding a few drops of:
a. Formic acid solution
b. Formaldehyde solution
c. Acetic acid solution
d. Acetaldehyde solution
Answer : B

Question. A coagulating agent frequently added to water to remove the suspended and colloidal impurities is:
a. Mohr salt
b. Alum
c. Bleaching powder
d. Copper sulphate
Answer : B

Question. Size of colloidal particle is:
a. 1 to 10 Å
b. 20 to 50 Å
c. 10 to 1000 Å
d. 1 to 280 Å
Answer : C

Question. Pick out the correct statements:
a. Gold sold does not act as a protective colloid
b. In a reaction that follows first order kinetics the fraction reacted is given by (1− e^−kt ) where ‘k’ is the rate constant
c. The temperature above which micellization takes place is known as reduced temperature
d. Hydrolysis of an ester by an alkali follows second order kinetics
Answer : A, B, D

Question. For coagulating As₂S₃ colloidal sol, which of the following will have the lowest coagulation value?
a. NaCl
b. KCl
c. BaCl₂
d. AlCl₃
Answer : D

Question. If some gelatin is mixed in colloidal solution of gold, then it does:
a. Coagulation of gold
b. Peptization of gold
c. Protection of gold sol
d. Protection of gelatin
Answer : C

Question. “Delta” at the rivers are formed due to:
a. Peptization
b. Coagulation
c. Hydrolysis
d. Precipitation
Answer : B

Question. Which of the following are correct statements?
a. Spontaneous adsorption of gases on solid surface is an exothermic process as entropy decreases during adsorption
b. Formation of micelles takes place when temperature is below Kraft temperature (T_k) and concentration is above critical micelle concentration (CMC)
c. A colloid of Fe (OH)₃ is prepared by adding NaOH in FeCl₃ solution, the particles of this sol will move towards cathode during electrophoresis
d. According to Hardy-Schulze rule the coagulation (flocculating) value of Fe³⁺ ion will be more than Ba²⁺ or Na⁺
Answer : A, C

Question. Which of the following statement(s) is true?
a. Lyphobic sol shows greater light scattering effect than lyophilic sol
b. the stability of lyophobic sol is due to presence of charge on sol particles
c. A catalyst increases the value of rate constant
d. The absolute entropy of an element is zero at 25°Cand 1 atm pressure
Answer : A, B, C

Question. Tyndall effect is shown by:
a. Sol
b. Solution
c. Plasma
d. Precipitation
Answer : A

Question. Which of the following colloids are formed when hydrogen sulphide gas is passed through a cold solution of arsenious oxide?
a. As₂S₃
b. As₂O₃
c. As₂S
d. As₂H₂
Answer : A

Question. Maximum coagulation power is in:
a. Na⁺
b. Ba⁺⁺
c. Al⁺⁺⁺
d. Sn⁺⁺⁺⁺
Answer : D

Question. Which one is an example of gel
a. Soap
b. Cheese
c. Milk
d. Fog
Answer : B

Question. Identify correct statement among the following:
a. Gold and As₂S₃ sols are multi-molecular colloids
b. This graph is for Van der Waal’s adsorption as explained by freundlich

d. Coagulation of gold sol is effective with Al³⁺ than with Mg²⁺
Answer : B, C

Match the Column

Question. Match the statement of Column with those in Column II:

Column I	Column II
(A) Gold number	1. Solvent heating
(B) Lyophobic	2. Coagulation
(C) Butter	3. Protective colloids
(D) Hardy Schulze rule	4. Solvent
(E) Micelles	5. Associated colloids
	6. An emulsion

a. A→ 3; B→ 4; C→ 6; D→ 2; E→ 5
b. A→ 2; B→ 4; C→ 3; D→ 5; E→ 1
c. A→ 1; B→ 3; C→ 6; D→ 4; E→ 2
d. A→ 4; B→ 1; C→ 3; D→ 2; E→ 5
Answer : A

Question. Match the statement of Column with those in Column II:

Column I	Column II
(A) Purple of cassius	1. Gel
(B) Cheese	2. Gold sol
(C) Dialysis	3. Robert Brown
(D) Brownian movement	4. Hydrophilic
(E) Water-loving colloids	5. Purification of colloidal solutions

a. A→ 3; B→ 1; C→ 4; D→ 2; E→ 5
b. A→ 2; B→ 5; C→ 3; D→ 1; E→ 4
c. A→ 2; B→ 1; C→ 5; D→ 3; E→ 4
d. A→ 4; B→ 1; C→ 3; D→ 5; E→ 2
Answer : C

Question. Match the statement of Column with those in Column II:

Column I	Column II
(A) Physisorption	1. Multimolecular
(B) Chemisorption	2. High heat of activation
(C) Activated adsorption	3. High temperature required
(D) Desorption	4. Low pressure required
(E) Electro-osmosis	5. Determination of charge on colloidal particles

a. A→ 1; B→ 2,3; C→ 2,3; D→ 4; E→ 5
b. A→ 2,3; B→ 4; C→ 3; D→ 1; E→ 5
c. A→ 1; B→ 3; C→ 2,3; D→ 5; E→ 4
d. A→ 4; B→ 5; C→ 3; D→ 2,3; E→ 1
Answer : A

 

CBSE Class 12 Chemistry Surface Chemistry Worksheet Set C

              Very Short Answer

Q1)       Define surface chemistry?

Q2)       What is desorption?

Q3)       What are the types of adsorption?

Q4)       Who gave the adsorption isotherm?

Q5)       Which type of adsorption involves high energy activation?

             

              Short Answer

Q6)       What do you mean by adsorption isotherm?

Q7)       How adsorbate is different from adsorbent?

Q8)       What are the important points for adsorption in action?

Q9)       What do you mean by mechanism of adsorption?

Q10)     What are the observations have been made in the case of adsorption from solution phase?

             

              Long Answer

Q11)     State the difference between chemisorption and physisorption?

Q12)     What are the characteristics of physisorption?

Q13)     State the difference between adsorption and desorption?

Q14)     What are the characteristics of the chemisorption?

Q15)     State the difference between adsorption and absorption?

 

Please click on below link to download CBSE Class 12 Chemistry Surface Chemistry Worksheet Set C