JEE Chemistry Surface Chemistry MCQs Set A

Question. Adsorbed acetic acid on activated charcoal is
(a) adsorbate
(b) absorber
(c) adsorber
(d) adsorbent

Answer: A

Question. Adsorption is always
(a) exothermic
(b) endothermic
(c) exothermic in case of physical and endothermic in case of chemical
(d) None of these

Answer: A

Question. Which is not correct regarding the physical adsorption of a gas on surface of solid
(a) On increasing temperature, adsorption increases continuously
(b) Enthalpy and entropy changes are negative
(c) Adsorption is more for some specific substance
(d) Reversible

Answer: A

Question. How many layers are adsorbed in chemical adsorption ?
(a) One
(b) Two
(c) Many
(d) Zero

Answer: A

Question. Adsorption due to strong chemical forces is called
(a) Chemisorption
(b) Physisorption
(c) Reversible adsorption
(d) None of these

Answer: A

Question. In physical adsorption, gas molecules are bound on the solid surface by
(a) van der Waal’s forces
(b) electrostatic forces
(c) chemical forces
(d) gravitational forces

Answer: A

Question. Which of the following statements is not correct
(a) Chemical adsorption first decreases with increase in temperature
(b) Physical adsorption is due to van der Waal’s forces
(c) Physical adsorption is reversible
(d) Adsorption energy for a chemical adsorption is generally greater than that of physical adsorption

Answer: A

Question. Adsorption of gases on solid surface is exothermic reaction because
(a) enthalpy is negative
(b) enthalpy is positive
(c) free energy increases
(d) entropy increases

Answer: A

Question. The gas which is least adsorbed on charcoal (under identical conditions) is
(a) O₂
(b) NH₃
(c) HCl
(d) CO₂

Answer: A

Question. Adsorption is accompanied by
(a) decrease in enthalpy and decrease in entropy
(b) increase in enthalpy and increase in entropy
(c) decrease in enthalpy and increase in entropy
(d) increase in enthalpy and decrease in entropy

Answer: A

Question. Choose the incorrect statement in respect of physisorption?
(a) Enthalpy of adsorption is in the range 80-240 kJ mol^–1
(b) It is reversible in nature
(c) It arises because of van der Waal’s force
(d) It is not specific in nature

Answer: A

Question. The term ‘sorption’ stands for ___________.
(a) both absorption and adsorption
(b) desorption
(c) adsorption
(d) absorption

Answer: A

Question. Extent of physisorption of a gas increases with
(a) decrease in temperature
(b) increase in temperature
(c) decrease in surface area of adsorbent.
(d) decrease in strength of van der Waal’s forces

Answer: A

Question. Extent of adsorption of adsorbate from solution phase increases with
(a) increase in amount of adsorbate in solution.
(b) decrease in surface area of adsorbent
(c) increase in temperature of solution
(d) decrease in amount of adsorbate in solution

Answer: A

Question. Which of the following is not a favourable condition for physical adsorption ?
(a) High temperature
(b) Higher critical temperature of adsorbate
(c) High pressure
(d) None of these

Answer: A

Question. Physical adsorption of a gaseous species may change to chemical adsorption with ________.
(a) increase in temperature
(b) decrease in temperature
(c) increase in surface area of adsorbent
(d) decrease in surface area of adsorbent

Answer: A

Question. In physisorption adsorbent does not show specificity for any particular gas because _________
(a) involved van der Waal’s forces are universal
(b) gases involved behave like ideal gases
(c) enthalpy of adsorption is low
(d) it is a reversible process

Answer: A

Question. Which of the following is an example of absorption
(a) Water on calcium chloride.
(b) Water on silica gel
(c) Hydrogen on finely divided nickel
(d) Oxygen on metal surface

Answer: A

Question. In Freundlich adsorption isotherm, the value of 1/n is
(a) between 0 and 1 in all cases
(b) between 2 and 4 in all cases
(c) 1 in case of physical adsorption
(d) 1 in case of chemisorption

Answer: A

Question. Which is adsorbed in maximum amount by activated charcoal ?
(a) CO₂
(b) O₂
(c) N₂
(d) Cl₂

Answer: A

Question. According to Freundlich adsorption isotherm, the amount of gas adsorbed at very high pressure
(a) reaches a constant limiting value
(b) goes on increasing with pressure
(c) increase first and decreases later with pressure
(d) None of these

Answer: A

Question. Which is not correct regarding the adsorption of a gas on surface of solid?
(a) On increasing temperature, adsorption increases continuously
(b) Enthalpy and entropy changes are –ve
(c) Adsorption is more for some specific substance
(d) This Phenomenon is reversible

Answer: A

Question. The role of a catalyst in a reversible reaction is to
(a) allow the equilibrium to be achieved quickly
(b) alter the equilibrium constant of the reaction
(c) decrease the rate of backward reaction
(d) increase the rate of forward reaction

Answer: A

Question.  Catalytic poisons act by
(a) preferential adsorption on the catalyst surface
(b) chemical combination with any one of the reactants.
(c) increasing the rate of the backward reaction
(d) making the products chemically inactive

Answer: A

Question. A catalyst
(a) lowers the activation energy
(b) changes the rate constant
(c) changes the product
(d) itself destroyed in the reaction

Answer: A

Question. Active charcoal is a good catalyst because it
(a) has more adsorption power
(b) has inert nature toward reagents
(c) is very reactive.
(d) is made up of carbon atoms

Answer: A

Question. Which of the following kind of catalysis can be explained by the adsorption theory ?
(a) Heterogeneous catalysis
(b) Enzyme catalysis
(c) Acid - base catalysis
(d) Homogeneous catalysis

Answer: A

Question. According to the adsorption theory of catalysis, the speed of the reaction increases because-
(a) Adsorption lowers the activation energy of the reaction
(b) The concentration of reactant molecules at the active centres of the catalyst becomes high due to strong adsorption
(c) In the process of adsorption, the activation energy of the molecules becomes large
(d) Adsorption produces heat which increases the speed of the reaction

Answer: A

Question. Catalyst increases the rate of reaction by
(a) decreasing activation energy
(b) increasing activation energy
(c) decreasing equilibrium constant
(d) decreasing threshold energy

Answer: A

Question. A catalyst can affect reversible reaction by
(a) attaining equilibria in both directions
(b) None of these
(c) slowing forward reaction
(d) changing equilibrium constant

Answer: A

Question. Which one of the following is an example of homogeneous catalysis
(a) Acid hydrolysis of methyl acetate
(b) Catalytic hydrogenation of oils
(c) Haber’s process of synthesis of ammonia
(d) None of these

Answer: A

Question. Identify the correct statement regarding enzymes
(a) Enzymes are specific biological catalysts that possess well-defined active sites
(b) Enzymes are normally heterogeneous catalysts that are very specific in their action
(c) Enzymes are specific biological catalysts that cannot be poisoned
(d) None of these

Answer: A

Question. A biological catalyst is
(a) an enzyme
(b) an amino acid
(c) a carbohydrate
(d) a nitrogenous base

Answer: A

Question. The action of enzymes in living system is to
(a) enhance the rate of biochemical reactions
(b) circulate oxygen
(c) enhance immunity
(d) supply energy to tissues

Answer: A

Question. In petrochemical industry alcohols are directly converted to gasoline by passing over heated
(a) ZSM-5
(b) Nickel
(c) Platinum
(d) Iron

Answer: A

Question. The dispersed phase and dispersion medium in soap lather are respectively
(a) gas and liquid
(b) solid and gas
(c) liquid and gas
(d) solid and liquid

Answer: A

Question. Which of the following is not a colloid ?
(a) Chlorophyll
(b) Ruby glass
(c) Smoke
(d) Milk

Answer: A

Question. Which of the following forms a colloidal solution in water ?
(a) Starch
(b) NaCl
(c) Glucose
(d) Barium nitrate

Answer: A

Question. Which of the following forms cationic micelles above certain concentration?
(a) Cetyl trimethyl ammonium bromide
(b) Urea
(c) Sodium acetate
(d) Sodium dodecyl sulphate

Answer: A

Question. Which of the following does not contain a hydrophobic structure ?
(a) Rubber
(b) Lanolin
(c) Linseed oil
(d) Glycogen

Answer: A

Question. Which one of the following is an example for multimolecular colloid?
(a) Aqueous starch sol
(b) Aqueous enzyme sol
(c) Alcoholic polystyrene sol
(d) Aqueous sol of sodium laurylsulphate

Answer: A

Question.  Bredig arc method cannot be used to prepare colloidal solution of which of the following
(a) Fe
(b) Au
(c) Pt
(d) Ag

Answer: A

Question. Colloidal solutions are not purified by
(a) Electrophoresis
(b) Electrodialysis
(c) Ultrafiltration
(d) Dialysis

Answer: A

Question. Colloid of which one of the following can be prepared by electrical dispersion method as well as reduction method ?
(a) Gold
(b) Ferric hydroxide
(c) Sulphur
(d) Arsenious sulphide

Answer: A

Question. Which of the following ions can cause coagulation of proteins ?
(a) Ag⁺
(b) Mg²⁺
(c) Na⁺
(d) Ca²⁺

Answer: A

Question.  Which of the following will be most effective in the coagulation of Al(OH)₃ sol ?
(a) Mg₃(PO₄)₂
(b) BaCl₂
(c) KCN
(d) NaCl

Answer: A

Question. 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) Mixing the sols has no effect
(b) Coagulation in both sols can be brought about by electrophoresis
(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.

Answer: A

Question. Point out the false statement
(a) The colloidal solution of a liquid in liquid is called gel
(b) Hardy Schulze rule is related with coagulation
(c) Brownian movement and Tyndall effect are shown by colloidal system
(d) Gold number is a measure of the protective power of lyophilic colloid

Answer: A

Question. A colloidal solution is subjected to an electric field. The particles move towards anode. The coagulation of same sol is studied using NaCl, BaCl₂ and AlCl₃ solutions. The order of their coagulation power should be –
(a) AlCl₃ > BaCl₂ > NaCl
(b) NaCl > BaCl₂ > AlCl₃
(c) BaCl₂ > AlCl₃ > NaCl
(d) None of these

Answer: A

Question. Flocculation value of BaCl₂ is much less than that of KCl for sol A and flocculation value of Na₂SO₄ is much less than that of NaBr for sol B. The correct statement among the following is
(a) Sol A is positively charged arid Sol B is negatively charged
(b) Both the sols A and B are positively charged
(c) Sol A is negatively charged and sol B is positively charged
(d) Both the sols A and B are negatively charged

Answer: A

Question. In Brownian movement or motion, the paths of the particles are
(a) Zig-zag
(b) Curved
(c) Linear
(d) Uncertain

Answer: A

Question. How does a delta form at the meeting place of sea and river water?
(a) The electrolyte present in sea water coagulate the clay
(b) the electrolyte present in sea water has no role
(c) the electrolyte present in river water coagulate the clay
(d) None of these

Answer: A

Question. _______ is a silver sol used as an eye lotion. Fill in the blank with an appropriate answer.
(a) Amytol
(b) Argyrol
(c) Ciprofloxacin
(d) None of these

Answer: A

Question. Which of the following will show Tyndall effect?
(a) Aqueous solution of soap above critical micelle concentration
(b) Aqueous solution of sodium chloride
(c) Aqueous solution of sugar
(d) Aqueous solution of soap below critical micelle concentration

Answer: A

Question. Which of the following combinations of dispersed phase and dispersion medium will not form a colloid ?
(a) Dispersed phase – Gas, Dispersion medium – Gas
(b) Dispersed phase – Solid, Dispersion medium – Gas
(c) Dispersed phase – Solid, Dispersion medium – Solid
(d) None of these

Answer: A

Question. Which of the following statements is incorrect?
(a) Tannin used in leather industry contains positively charged colloidal particles
(b) Photographic films are prepared by coating an emulsion of AgBr in gelatin over glass plate
(c) Colloidal solution of latex is used in preparation of rubber
(d) Colloidal gold is used for intramuscular injection

Answer: A

Question. Which of the following is not correctly matched
(a) Gold sol – Double decomposition
(b) Sulphur sol – Oxidation
(c) Fe(OH)₃ sol – Hydrolysis
(d) None of these

Answer: A