NEET Chemistry Chapter Wise Mock Test – Surface Chemistry
Question 1:
Adsorbed acetic acid on activated charcoal is
(a) adsorber
(b) adsorbent
(c) adsorbate
(d) absorber
Question 2:
Which of the following is not applicable to the phenomenon of adsorption?
(a) ΔH >0
(b) ΔG<0
(c) ΔS<0
(d) ΔH<0
Question 3:
50 mL of 1 M oxalic acid (molar mass = 126) is shaken with 0.5 g of wood charcoal. The final concentration of the solution after adsorption is 0.5 M. What is the amount of oxalic acid adsorbed per gram of carbon?
(a) 3.15
(b) 1.575
(c) 6.30
(d) 12.60
Question 4:
At the equilibrium position in the process of acfeorption
(a) ΔH >0
(b) ΔH<TΔS
(c)ΔH>TΔS
(d)ΔH<TΔS
Question 5:
Adsorption in multilayer occurs in case of
(a) physical adsorption
(b) chemical adsorption
(c) Both (a) and (b)
(d) None of the above
Question 6:
Which one of the following characteristics is not correct for physical adsorption?
(a) Adsorption on solids is reversible
(b) Adsorption increases with increase in temperature
(c) Adsorption is spontaneous
(d) Both enthalpy and entropy of adsorption are negative
Question 7:
The heats of adsorption in physisorption lies in range (in kJ/mol)
(a) 40 – 400
(b) 10-40
(c) 200 – 400
(d) 40-100
Question 8:
Adsorption due to strong chemical force is called
(a) chemisorption
(b) physisorption
(c) reversible adsorption
(d) Any of the above
Question 9:
Question 10:
Plot of log x/m against log p is a straight line inclined at an angle of 45°. When the pressure is 0.5 atm and Freundlich parameter k is 10, the amount of solute adsorbed per gram of adsorbent will be (log 5 = 0.6990)
(a) 1 g
(b) 2 g
(c) 3 g
(d) 5 g
Question 11:
The Langmuir adsorption isotherm ia deduced using the assumption
(a) the adsorption takes place is monolayer
(b) the adsorption sites are equivalent in their ability to adsorb the particles
(c) the heat of adsorption varies with coverage
(d) the adsorbed molecules interact with each other
Question 12:
Question 13:
Which one 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 of sucrose in presence of dilute hydrochloric acid
(d) Hydrogenation of oil
Question 14:
Which of the following process does not occur at the interface of phases?
(a) Crystallisation
(b) Heterogeneous catalysis
(c) Homogeneous catalysis
(d) Corrosion
Question 15:
Question 16:
Question 17:
According to the adsorption theory of catalysis, the speed of 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 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
Question 18:
The efficiency of enzyme catalysis is due to its capacity to
(a) form a strong enzyme-substrate complex
(b) change the shape of the substrate
(c) lower the activation energy of the reaction
(d) form a colloidal solution in water
Question 19:
The enzyme which can catalyse the conversion of glucose to ethanol is
(a) zymase
(b) invertase
(c) maltase
(d) diastase
Question 20:
Colloidal solution of gold prepared by different methods are of different colours because of
(a) variable valency of gold
(b) different concentrations of gold particles
(c) impurities produced by different methpds
(d) different diameters of colloidal gold particles
Question 21:
When HgS is passed through nitric acid, the product is
(a) rhombic (S)
(b) prismatic (S)
(c) monclinic (S)
(d) amorphous (S)
Question 22:
Cellulose dispersed in ethanol is called
(a) emulsion
(b) micelle
(c) collodion
(d) hydrophilic sol
Question 23:
Bredig’s arc method cannot be used to prepare colloidal solution of which of the following?
(a) Pt
(b) Fe
(c) Ag
(d) Au
Question 24:
The density of gold is 19 g/cm3. If 1.9x 10-4. g of gold is dispersed in 1 L of water to give a sol having spherical gold particles of radius 10 nm, then the number of gold particles per mm3.of the sol will be
(a) 1.9x 1012
(b)6.3×1014
(c) 6.3 x 1010
(d) 2.4 x 106
Question 25:
At high concentration of soap in water, soap behaves as
(a) nrftifecular colloid
(b) associated colloid
(c) macro molecular colloid
(d) lisophilic colloid
Question 26:
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
Question 27:
Which of the following forms cationic micelles above certain concentrations?
(ap£bdium ethyl sulphate
(b) Sodium acetate
(c) Urea
(d) Cetyltrimethyl ammonium bromide
Question 28:
Lyophilic colloids are stable due to
(a) charge on particles
(b) large size of the particle
(c) small size of the particles
(d) layer of dispersion medium on the particles
Question 29:
Which of the following process is responsible for the formation of delta at a place where rivers meet the sea?
(a) Emulsification
(b) Colloid formation
(c) Coagulation
(d) Peptisation
Question 30:
Tyndall effect is more pronounced in
(a) hydrophilic sols
(b) hydrophobic sols
(c) lyophilic sols
(d) Both (a) and (b)
Question 31:
Blood may be purified by
(a) dialysis
(b) electro-osmosis
(c) coagulation
(d) filtration
Question 32:
Which of the following electrolytes is least effective in coagulating ferric hydroxide solution?
(a) KBr
(b) K2S04
(c) K2Cr04
(d) K4[Fe(CN)6]
Question 33:
Milk can be preserved by adding a few drops of
(a) formic acid solution
(b) formaldehyde solution
(c) acetic acid solution
(d) acetaldehyde solution
Question 34:
The concentration of electrolyte required to coagulate a given amount of As2S3 sol is minimum in case of
(a) K2S04
(b)AI(N03)3
(c)Mg(N03)2
(d)KN03
Question 35:
Which is more powerful to coagulate the negative colloid?
(a) ZnS04
(b) Na3P04
(c) AICI3
(d) K4[Fe(CN)6]
Question 36:
The coagulation values of AICI3 and NaCI are 0.093 and 52 respectively. The ratio of coagulating power of both will be
(a) 0.093 : 1
(b) 52 : 1
(c) 559 : 1
(d) 1.788 : 1
Question 37:
Alum helps in purifying water by
(a) forming Si complex with dirt particles
(b) sulphate part which combines with dirt and removes it
(c) making mud water soluble
(d) aluminium ions which coagulates the mud particle
Question 38:
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 FeCI3 and haemoglobin
Question 39:
On adding 1 ml of solution of 10% NaCI 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) 25
(d) 250
Question 40:
Milk is
(a) fat dispersed in water
(b) fat dispersed in milk
(c) fat dispersed in fat
(d) water dispersed in milk
Question 41:
Which of the following substances will precipitate the negatively charged emulsions? [NCERT Exemplar] I. KCI II. glucose III. urea IV. NaCI
The correct answer is
(a) I and II
(b) I and III
(c) I and IV
(d) II and III
Question 42:
An emulsion cannot be broken by and
I. heating
II.adding more amount of dispersion medium
III.freezing
IV.adding emulsifying agent The correct answer is
(a) I and II
(b) II and III
(c) II and IV
(d) I, II and III
Direction (Q. Nos. 43-44) In the following questions, more than one of the answers given may be correct. Select the answers and mark it according to the codes.
Codes
(a) 1,2 and 3 are correct
(b) 1 and 2 are correct
(c) 2 and 4 are correct
(d) 1 and 3 are correct
Question 43:
Which among the following statements are correct with respect to adsorption of gases on a solid?
1. The extent of adsorption is equal to kpn according to Freundlich isotherm.
2. The extent of adsorption is equal to kp1/n according to Freundlich isotherm.
3. The extent of adsorption is equal to (1 + bp)/ap according to Langmuir isotherm.
4. The extent of adsorption is equal to ap/(1 + bp) according to Langmuir isotherm.
Question 44:
Which of the following statements are true for hydrophilic solution?
1. They do not require electrolytes for stability.
2. Their coagulation is irreversible.
3. Their surface tension is usually lower than that of dispersion medium.
4. Their viscosity is of the order of that of water.
Question 45:
Question 46:
Direction (Q. Nos. 47-51) Each of these questions contains two statements: Assertion and Reason. Each of these questions also has four alternative choices, only one of which is the correct answer. You have to select one of the codes (a), (b), (c) and (d) given below.
(a) Assertion is true, Reason is true; Reason is a correct explanation for Assertion
(b) Assertion is true, Reason is true; Reason is not a correct explanation for Assertion
(c) Assertion is true, Reason is false
(d) Assertion is false, Reason is true
Question 47:
Assertion An emulsion becomes stable if soap is added to it.
Reason Soap contains both hydrophilic and hydrophobic parts.
Question 48:
Assertion The activity of a catalyst depends upon the strength of physisorption.
Reason The reactant must adsorb very strongly for the catalyst to be active.
Question 49:
Assertion Aqueous gold colloidal solution is red in colour.
Reason The colour arises due to scattering of light by colloidal gold particles.
Question 50:
Assertion A catalyst increases the rate of a reaction.
Reason In presence of a catalyst, the activation energy of the reaction decreases.
Question 51:
Assertion In chemisorption, adsorption keeps on increasing with temperature
Reason Heat keeps on providing more and more activation energy.
Question 52:
Which property of colloidal solution is independent of charge on the colloidal particles?
(a) Coagulation
(b) Electrophoresis
(c) Electro-osmosis
(d) Tyndall effect
Question 53:
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
Question 54:
The protecting power of lyophilic colloidal sol is expressed in terms of
(a) coagulation value
(b) gold number
(c) critical micelle concentration
(d) oxidation number
Question 55:
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
Question 56:
Purple of cassius is a/an
(a) colloidal sol of gold
(b) colloidal sol of silver
(c) colloidal sol of platinum
(d) oxyacid of gold
Question 57:
Question 58:
The simplest way to check whether a system is colloidal is
(a) electrodialysis
(b) finding out particle size
(c) Tyndall effect
(d) Brownian movement
Question 59:
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
Question 60:
The Brownian motion is due to
(a) temperature fluctuation within the liquid phase
(b) attraction and repulsion between charges on the colloidal particles
(c) impact of the molecules of the dispersion
(d) convectional currents
Answers:
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