NEET Chemistry Surface Chemistry MCQs Set A

Question: Which one of the following is a property of physisorption?

• a) Non-specific nature
• b) High specificity
• c) Irreversibility
• d) Single layer adsorption

Answer: Non-specific nature

Question: Which of the following is not a characteristic of chemisorption?

• a) Irreversible nature
• b) ΔH is of the order of 500 J
• c) Specific in nature
• d) Increases with increase of surface area

Answer:  ΔH is of the order of 500 J

Question: Freundlich adsorption isotherm gives a straight line on plotting

• a) x/m versus P
• b) log x/m versus P
• c) log x/m versus log P
• d) x/m versus 1/P

Answer: log x/m versus log P

Question: Which can adsorb larger volume of hydrogen gas?

• a) Colloidal solution of palladium
• b) Finely divided nickel
• c) Finely divided platinum
• d) Colloidal Fe(OH)₃

Answer: Colloidal solution of palladium

Question: The process of froth floatation and chromatography are based on

• a) Emulsification
• b) Adsorption
• c) Absorption
• d) Both (2) & (3)

Answer: Adsorption

Question:  The graph plotted against adsorption versus pressure P at constant temperature, the Freundlich equation at points A, B, C respectively are (if n > 1)

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:   The intercept on Y-axis in the graph of   versus log P gives

• a)

  

• b) k
• c) log k
• d) Temperature

Answer: log k

Question:  Which of the following is correct about the adsorption of N₂ over Iron?

• a) It is always physically adsorbed
• b) Extent of adsorption over iron decreases with the increase in temperature first and then increases
• c) It is always chemically adsorbed
• d) N₂ is never adsorbed over iron

Answer: Extent of adsorption over iron decreases with the increase in temperature first and then increases

Question: By plotting log x/m on y-axis and log P on x-axis, we should get

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: In adsorption from solution phase, the Freundlich adsorption isotherm is modified as

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: Which is not a colloidal solution?

• a) Smoke
• b) Ink
• c) Air
• d) Blood

Answer: Air

Question: Lyophobic colloids are

• a) Reversible colloids
• b) Irreversible colloids
• c) Protective colloids
• d) Gum, proteins

Answer: Irreversible colloids

Question: Size of colloidal particle ranges between

• a) 1 nm to 100 nm
• b) 1 nm to 1000 nm
• c) 10 nm to 1000 nm
• d) 100 nm to 1000 nm

Answer: 1 nm to 1000 nm

Question: Which of the following processes best describes the purification of muddy water by addition of alum?

• a) Absorption
• b) Coagulation
• c) Dialysis
• d) Electrodialysis

Answer: Coagulation

More Questions........................................................

Question: Colloidal solution commonly used in treatment of eye disease is

• a) Colloidal sulphur
• b) Colloidal silver
• c) Colloidal gold
• d) Colloidal antimony

Answer: Colloidal silver

Question: Micelles formation takes place

• a) At CMC and at kraft temperature
• b) At CMC and at above kraft temperature
• c) At above CMC and at kraft temperature
• d) Above CMC and above kraft temperature

Answer: Above CMC and above kraft temperature

Question: Colloids can be purified by

• a) Tyndall effect
• b) Coagulation
• c) Peptization
• d) Ultrafiltration

Answer: Ultrafiltration

Question: Which of the following has minimum protecting power?

• a) Gelatin (Gold no. = 0.01)
• b) Dextrin (Gold no. = 15)
• c) Potato starch (Gold no. = 25)
• d) Albumin (Gold no. = 0.25)

Answer: Potato starch (Gold no. = 25)

Question: Which of the following is positively charged colloidal particle?

• a) As₂S₃
• b) Al₂O₃.xH₂O 
• c) Au
• d) Pt

Answer:  Al₂O₃.xH₂O 

Question: Movement of colloidal particles under the influence of electric field is called

• a) Electrophoresis
• b) Dialysis
• c) Ionisation
• d) Electrodialysis

Answer: Electrophoresis

Question: Emulsifier is an agent which

• a) Accelerates the dispersion
• b) Stabilises the emulsion
• c) Homogenizes the emulsion
• d) Dissociate emulsions

Answer: Stabilises the emulsion

Question: Gelatin is often used as an ingredient in the manufacture of ice-cream. The reason for this is

• a) To prevent the formation of a colloid
• b) To stabilize the colloid and prevent crystal growth
• c) To cause the mixture to solidify
• d) To improve the flavour

Answer: To stabilize the colloid and prevent crystal growth

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: Formaldehyde solution

Question: When a river enters the sea, a delta is formed. Formation of delta is due to

• a) Peptization
• b) Coagulation
• c) Emulsification
• d) Dialysis

Answer: Coagulation

Question: Which statement is incorrect?

• a) Higher the gold number of lyophilic sol better is its protective action
• b) Lower the gold number of a lyophilic sol better is its protective action
• c) The Bredig's arc method is usually suitable for preparing sols of inert metals
• d) The osmotic pressure method gives the average molar mass of a polymer

Answer: Higher the gold number of lyophilic sol better is its protective action

Question: The potential difference between the fixed charged layer and the diffused layer having opposite charge is called

• a) Zeta potential
• b) Streaming potential
• c) Dorn potential
• d) Colloidal potential

Answer: Zeta potential

Question:  When dilute aqueous solution of AgNO₃ (excess) is added to KI solution, positively charged sol particles of AgI are formed due to adsorption of ion

• a) K⁺ 
• b) Ag⁺ 
• c) I^– 
• d) NO₃^–

Answer:  Ag⁺ 

Question:  In the preparation of AgI sol, AgNO₃ is added to excess of potassium iodide solution. The particles of the sol will acquire

• a) Negative charge
• b) Positive charge
• c) No charge
• d) Unpredictable

Answer: Negative charge

Question: Which of the following method is not employed for the purification of colloids?

• a) Electrodialysis
• b) Dialysis
• c) Ultracentrifugation
• d) Peptisation

Answer: Peptisation

Question: During purification of colloidal sol by ultracentrifugation which of the following is observed?

• a) Colloidal particles are settled at the bottom of ultracentrifuge tube
• b) Impurities are settled at the bottom of the ultracentrifuge tube
• c) Impurities are removed through ultrafilters
• d) It’s rate can be increased by applying pressure

Answer: Colloidal particles are settled at the bottom of ultracentrifuge tube

Question: A positive colloid will be formed when

• a) NH₄OH is added dropwise in dilute solution of FeCl₃
• b) H₂S is passed in dilute AsCl₃ solution
• c) Dilute AgNO₃ solution is added to saturated AgI solution
• d) Gelatin is dissolved in water

Answer:  Dilute AgNO₃ solution is added to saturated AgI solution

Question:  Which of the following is with highest and lowest flocculation value among Al⁺³, Na⁺, Mg⁺², Ba⁺²?

• a) Al⁺³, Na⁺
• b) Na⁺, Al⁺³
• c) Ba⁺², Al⁺³
• d) They have same flocculation value

Answer:  Na⁺, Al⁺³

Question: Most effective coagulant for a colloidal solution of arsenic sulphide in water is

• a) 0.1 M sodium phosphate
• b) 0.1 M zinc sulphate
• c) 0.1 M zinc nitrate
• d) 0.1 M aluminium chloride

Answer: 0.1 M aluminium chloride

Question: Flocculation value is expressed in terms of

• a) Millimoles of electrolyte per litre of solution
• b) Moles of electrolyte per litre of solution
• c) Gram of electrolyte per litre of solution
• d) Millimoles of electrolyte per millilitre of solution

Answer: Millimoles of electrolyte per litre of solution

Question: Colloidal particles in soap sol carry

• a) Negative charge
• b) Positive charge
• c) No charge
• d) Either positive or negative charge

Answer: Negative charge

Question: Which of the following metallic sols cannot be prepared by Breding’s arc method?

• a) Gold
• b) Silver
• c) Platinum
• d) Sodium

Answer: Sodium

Question: The stabilization of the dispersed phase in a lyophobic sol is due to

• a) The viscosity of the medium
• b) The surface tension of the medium
• c) Affinity for the medium
• d) The formation of an electrical double layer between the two phases

Answer: The formation of an electrical double layer between the two phases

Question:  When SO₂ gas is bubbled into H₂S gas

• a) Lyophillic sol of sulphur is formed
• b) Lyophobic sol of sulphur is formed
• c) Suspension of water and sulphur is formed
• d) A true solution of sulphur in water is formed

Answer: Lyophobic sol of sulphur is formed

Question:  When FeCl₃ solution is added to NaOH a negatively charged sol is obtained. It is due to the

• a) Presence of basic group
• b) Preferential adsorption of OH^– ions
• c) Self dissociation
• d) Electron capture by sol particles

Answer: Electron capture by sol particles

Question: The example of homogeneous catalysis is

• a) Formation of NH₃ in Haber's process 
• b) Formation of NO in Ostwald's process
• c) Formation of SO₃ in Lead chamber process 
• d) Formation of SO₃ in Contact process

Answer:  Formation of SO₃ in Lead chamber process 

Question: Which property of colloidal solution is independent of charge on the colloidal particles?

• a) Tyndall effect
• b) Coagulation
• c) Electrophoresis
• d) Electro-osmosis

Answer: Tyndall effect

Question: Which property of colloids is not dependent on the charge on colloidal particles?

• a) Coagulation
• b) Electrophoresis
• c) Electro-osmosis
• d) Tyndall effect

Answer: Tyndall effect

Question: Which one of the following statement is incorrect about enzyme catalysis?

• a) Enzymes are denaturated by ultraviolet rays and at high temperature
• b) Enzymes are least reactive at optimum temperature
• c) Enzymes are mostly proteinous in nature
• d) Enzyme action is specific

Answer: Enzymes are least reactive at optimum temperature

Question: In Freundlich Adsorption isotherm, the value of 1/n is

• a) 1 in case of physical adsorption
• b) 1 in case of chemisorption
• c) Between 0 and 1 in all cases
• d) Between 2 and 4 in all cases

Answer: Between 0 and 1 in all cases

Question: Which of the following statements is correct for the spontaneous adsorption of a gas?

• a) ΔS is negative and, therefore, ΔH should be highly positive
• b) ΔS is negative and therefore, ΔH should be highly negative
• c) ΔS is positive and, therefore, ΔH should be negative 
• d) ΔS is positive and, therefore, ΔH should also be highly positive

Answer:  ΔS is negative and therefore, ΔH should be highly negative

Question: The protecting power of lyophilic colloidal sol is expressed in terms of

• a) Critical miscelle concentration
• b) Oxidation number
• c) Coagulation value
• d) Gold number

Answer: Gold number

Question: If x is amount of adsorbate and m is amount of adsorbent, which of the following relations is not related to adsorption process?

• a)

  

• b) x/m = f(p) at constant T
• c) x/m = f(T) at constant P
• d) p = f(T) at constant (x/m)

Answer:

Question: The Langmuir adsorption isotherm is deduced using the assumption

• a) The adsorbed molecules interact with each other
• b) The adsorption takes place in multilayers
• c) The adsorption sites are equivalent in their ability to adsorb the particles
• d) The heat of adsorption varies with coverage

Answer: The adsorption sites are equivalent in their ability to adsorb the particles

Question: A plot of log x/m versus log p for the adsorption of a gas on a solid gives a straight line with slope equal to

• a) – log k
• b) n
• c) 1/n
• d) log k

Answer: 1/n

Question: Which one of the following forms micelles in aqueous solution above certain concentration?

• a) Urea
• b) Dodecyl trimethyl ammonium chloride
• c) Pyridinium chloride
• d) Glucose

Answer: Dodecyl trimethyl ammonium chloride

Question: When a few typical solutes are separated by a particular selective membrane such as protein particles, blood corpuscles, this process is called

• a) Transpiration
• b) Endosmosis
• c) Dialysis
• d) Diffusion

Answer: Dialysis

Question: The ability of anion, to bring about coagulation of a given colloid, depends upon

• a) Magnitude of the charge
• b) Both magnitude and sign of charge
• c) Its charge only
• d) Sign of the charge alone

Answer: Both magnitude and sign of charge

Question: A colloidal system has particles of which of the following size?

• a) 10^–9 m to 10^–12 m
• b) 10^–6 m to 10^–9 m
• c) 10^–4 m to 10^–10 m
• d) 10^–5 m to 10^–7 m

Answer:  10^–6 m to 10^–9 m

Question: At the critical micelle concentration (CMC) the surfactant molecules

• a) Associate
• b) Dissociate
• c) Decompose
• d) Become completely soluble

Answer: Associate

Question: Which one of the following method is commonly used method for destruction of colloid?

• a) Dialysis
• b) Condensation
• c) Filteration by animal membrane
• d) By adding electrolyte

Answer: By adding electrolyte

Question: Pure water can be obtained from sea water by

• a) Centrifugation
• b) Plasmolysis
• c) Reverse osmosis
• d) Sedimentation

Answer: Reverse osmosis

Question: Which is not correct regarding the adsorption of a gas on surface of a solid?

• a) On increasing temperature adsorption increases continuously
• b) Enthalpy and entropy change is negative
• c) Adsorption is more for some specific substance
• d) It is a reversible reaction

Answer: On increasing temperature adsorption increases continuously

Question: Position of non polar and polar part in micelle

• a) Polar at outer surface but non polar at inner surface
• b) Polar at inner surface non polar at outer surface
• c) Distributed over all the surface
• d) Are present in the surface only

Answer: Polar at outer surface but non polar at inner surface

Question: According to the adsorption theory of catalysis, the speed of the reaction increases because

• a) The concentration of reactant molecules at the active centres of the catalyst becomes high due to adsorption
• b) In the process of adsorption, the activation energy of the molecules becomes large
• c) Adsorption produces heat which increases the speed of the reaction
• d) Adsorption lowers the activation energy of the reaction

Answer: Adsorption lowers the activation energy of the reaction

Question: Which of the following forms cationic micelles above certain concentration?

• a) Sodium dodecyl sulphate
• b) Sodium acetate
• c) Urea
• d) Cetyltrimethylammonium bromide

Answer: Sodium dodecyl sulphate