JEE Chemistry Surface Chemistry MCQs Set C

Question. Which one of the following impurities present in colloidal solution cannot be removed by electrodialysis
(a) Urea
(b) Sodium chloride
(c) Potassium sulphate
(d) Calcium chloride

Answer: A

Question. Brownian movement is found in
(a) Suspension
(b) Unsaturated solution
(c) Colloidal solution
(d) Saturated solution

Answer: A

Question. Random motion of colloidal particles is known as
(a) Brownian movement
(b) Tyndall effect
(c) Dialysis
(d) Electroosmosis

Answer: A

Question. In which of the following Tyndall effect is not observed ?
(a) Sugar solution
(b) Suspensions
(c) Emulsions
(d) Gold sol

Answer: A

Question. Which of the following is not true about the emulsion?
(a) Emulsion do not show the Tyndall effect
(b) They show brownian motion
(c) Emulsion of oil in water is generally unstable
(d) Emulsion can be broken into constituent liquids by heat, freezing

Answer: A

Question. Which of the following process is responsible for the formation of delta at a place where rivers meet the sea?
(a) Coagulation
(b) Emulsification
(c) Colloid formation
(d) Peptisation

Answer: A

Question. Which of the following colloid does not contain liquid as a dispersion medium?
(a) Gel
(b) Foam
(c) Sol
(d) Emulsion

Answer: A

Question.  Which of the following method is used for coagulation of the sol?
(a) All of the above.
(b) By addition of electrolytes
(c) By electrophoresis
(d) By mixing two oppositely charged sols

Answer: A

Question. Which of the following phenomenon occurs when the precipitate of Mg(OH)₂ attains blue colour in presence of magneson reagent?
(i) Absorption of solvent
(ii) Adsorption of coloured substance
(iii) Absorption and adsorption both of solvent
(iv) Adsorption of solvent
(a) (ii) and (iv)
(b) (i) and (ii)
(c) (ii) only
(d) (iii) only

Answer: A

Question. Which of the following is not the condition for Tyndall effect?
(a) Tyndall effect is observed only when viewed from the direction of the passage of light
(b) All of these are required conditions for Tyndall effect
(c) The diameter of the dispersed particles is not much smaller than the wavelength of light used.
(d) The refractive indices of dispersed phase and dispersion medium should differ greatly in magnitude

Answer: A

Question. Which of the following is not emulsifying agent for W/O emulsion?
(a) Proteins
(b) Long chain alcohol
(c) Lampblack
(d) Heavy metal salts of fatty acids

Answer: A

Question. Emulsions can be broken into constituent liquid by
(a) All of these
(b) freezing
(c) heating
(d) centrifuging

Answer: A

Question. Read the following statements regarding adsorption and choose the correct option.
(i) It is a surface phenomenon.
(ii) The material which is adsorbed is termed as adsorbate.
(iii) The material on the surface of which the adsorption takes place is called adsorbent.
(iv) Adsorption is a bulk phenomenon
(a) (i), (ii) and (iii) are correct
(b) (i), (ii) and (iv) are correct
(c) (i) and (ii) are correct
(d) Only (iv) is correct

Answer: A

Question. Read the following statements related to physisorption
(i) Adsorbent shows preference for gases with high molecular weight.
(ii) Easily liquefiable gases gets readily adsorbed.
(iii) Adsorption varies with change in temperature and pressure.
(iv) Finely divided and solid metals adsorb gases equally.
(v) It is exothermic with low value of enthalpy of adsorption.
Which of the following is the correct code for the statements above ?
(a) FTTFT
(b) FTTTF
(c) TFFTF
(d) TFFTT

Answer: A

Question. Read the following statements related to chemisorption
(i) It is highly specific.
(ii) It increases with increase in temperature and pressure.
(iii) It is reversible.
(iv) It increases with increase in surface area of adsorbent.
Which of the following is correct code for the statements above
(a) TTFT
(b) FTFT
(c) TFFT
(d) FFTF

Answer: A

Question. Which of the following statement(s) is/are correct?
(i) Zeolites are good shape selective catalysts because of their honeycomb-like structures.
(ii) All zeolites are naturally occurring substance.
(iii) An important zeolite catalyst used in the petroleum industry in ZSM-5.
(a) (i) and (iii)
(b) (i) only
(c) (ii) and (iii)
(d) (ii) only

Answer: A

Question. Read the following statements
(i) Tyndall effect is used to distinguish between a colloidal and true solution.
(ii) Values of colligative properties are same for true and colloidal solutions.
(iii) Random bombardment of the colloidal particles by the molecules of the dispersion medium does not allow colloids to settle thereby providing stability to them.
(iv) Most acceptable phenomena to account for the charge of sol particles is electrodispersion.
Which of the following is the correct code for statements above?
(a) TFTF
(b) TTFF
(c) FTFT
(d) TFFT

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. Assertion : The enthalpy of physisorption is greater than chemisorption.
Reason : Molecules of adsorbate and adsorbent are held by van der Waal’s forces in physisorption and by chemical bonds in chemisorption
(a) Assertion is incorrect, reason is correct
(b) Assertion is correct, reason is incorrect
(c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(d) Assertion is correct, reason is correct; reason is a correct explanation for assertion

Answer: A

Question. Assertion: Detergents with low CMC are more economical to use.
Reason: Cleansing action of detergents involves the formation of micelles. These are formed when the concentration of detergents becomes equal to CMC.
(a) Assertion is correct, reason is correct; reason is a correct explanation for assertion
(b) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(c) Assertion is correct, reason is incorrect
(d) Assertion is incorrect, reason is correct

Answer: A

Question. Assertion : The value of colligative properties are of small order for colloids as compared to true solution.
Reason : Number of particles in colloidal solution is comparatively smaller than true solutions.
(a) Assertion is correct, reason is correct; reason is a correct explanation for assertion
(b) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(c) Assertion is correct, reason is incorrect
(d) Assertion is incorrect, reason is correct

Answer: A

Question. Assertion: An ordinary filter paper impregnated with collodion solution stops the flow of colloidal particles.
Reason: Pore size of the filter paper becomes more than the size of colloidal particle.
(a) Assertion is correct, reason is incorrect
(b) Assertion is incorrect, reason is correct
(c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(d) Assertion is correct, reason is correct; reason is a correct explanation for assertion

Answer: A

Question. Which is correct about physical adsorption?
(a) Low temperature and high pressure favour adsorption
(b) Low temperature and low pressure favour adsorption
(c) High temperature and low pressure favour adsorption
(d) High temperature and high pressure favour adsorption

Answer: A

Question. Methylene blue, from its aqueous solution, is adsorbed on activated charcoal at 25°C. For this process, which of the following statement is correct ?
(a) The adsorption is accompanied by a decrease in enthalpy
(b) The adsorption increases with increase of temperature
(c) The adsorption is irreversible
(d) The adsorption requires activation at 25°C

Answer: A

Question. In the adsorption of a gas on solid, Freundlich isotherm is obeyed. The slope of the plot is zero. Then the extent of adsorption is
(a) independent of the pressure of the gas
(b) directly proportional to the square root of the pressure of the gas
(c) inversely proportional to the pressure of the gas
(d) directly proportional to the pressure of the gas

Answer: A

Question. Which of the following statements regarding difference between adsorption and absorption is incorrect?
(a) Adsorption and absorption take place individually. They can not occur simultaneously.
(b) All of the above statements are correct
(c) Water vapours are absorbed by anhydrous CaCl₂ but adsorbed by silica gel.
(d) Adsorption is a surface whereas absorption is a bulk phenomena

Answer: A

Question. Which of the following is not an application of adsorption?
(a) In homogeneous catalysis
(b) Separation of inert gas.
(c) In heterogeneous catalysis involving solid catalyst
(d) In metallurgy for concentration of sulphide ores

Answer: A

Question. Which of the following statements about a catalyst is true ?
(a) A catalyst accelerates the reaction by bringing down the free energy of activation
(b) A catalyst also takes part in the reaction mechanism
(c) A catalyst makes the equilibrium constant of the reaction more favourable for the forward reaction
(d) None of these

Answer: A

Question. Which one of the following, statements is incorrect about enzyme catalysis?
(a) Enzymes are least reactive at optimum temperature
(b) Enzymes are denaturated by ultraviolet rays and at high temperature
(c) Enzyme action is specific.
(d) Enzymes are mostly protenious in nature

Answer: A

Question. Given below, catalyst and corresponding process/reaction are matched. The one with mismatch is
(a) V₂O₅ : Haber-Bosch process
(b) Nickel : Hydrogenation
(c) Both
(d) None of these

Answer: A

Question. Which one of the following statements is incorrect in the case of heterogeneous catalysis ?
(a) The surface of the catalyst plays a very important role
(b) There is no change in the energy of activation
(c) The catalyst actually forms a compound with the reactant
(d) The catalyst lowers the energy of activation

Answer: A

Question. Which of the following statements regarding catalyst is not true ?
(a) A catalyst can initiate a reaction
(b) A catalyst does not alter the equilibrium in a reversible reaction
(c) Catalysts are sometimes very specific in respect of reaction
(d) A catalyst remains unchanged in composition and quantity at the end of the reaction

Answer: A