Surface Chemistry PYQs Set 5 (PDF)

Set 5 of 9 · Questions 121-150 of 248

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Mere Teacher · Previous Year Questions

JEE Main Chemistry · Surface Chemistry · Set 5 (Q121-150)

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121.
During the adsorption of a gas on the surface of a solid, which of the following is true?
1. (1) $Δ G < 0, Δ H > 0, Δ S < 0$
2. (2) $Δ G > 0, Δ H < 0, Δ S < 0$
3. (3) $Δ G < 0, Δ H < 0, Δ S < 0$
4. (4) $Δ G < 0, Δ H < 0, Δ S > 0$
122.
This equation represents the preparation of gold sol by
$2 AuCl_{3} + 3 HCHO + 3 H_{2} O \to 2 Au + 3 HCOOH + 6 HCl .$
1. (1) $Oxidation$
2. (2) $Reduction$
3. (3) $Double decomposition$
4. (4) $Hydrolysis$
123.
Which is not correct regarding the adsorption of a gas on surface of a solid?
1. (1) $On increasing temperature adsorption increases continuously.$
2. (2) $Enthalpy and entropy change is negative.$
3. (3) $Adsorption is more for some specific substance.$
4. (4) $It is a reversible reaction.$
124.
Adsorption of a gas on a surface follows Freundlich adsorption isotherm. Plot of log $\frac{x}{m}$ versus log p gives a straight line with slope equal to 0.5, then: ( $\frac{x}{m}$ is the mass of the gas adsorbed per gram of adsorbent)
1. (1) $Adsorption is proportional to the pressure.$
2. (2) $Adsorption is proportional to the square root of pressure.$
3. (3) $Adsorption is proportional to the square of pressure.$
4. (4) $Adsorption is independent of pressure.$
125.
0.27 g of a long chain fatty acid was dissolved in $100 c m^{3}$ of hexane. 10 mL of this solution was added dropwise to the surface of water in a round watch glass. Hexane evaporates and a monolayer is formed. The distance from edge to centre of the watch glass is 10 cm. what is the height of the monolayer ? [Density of fatty acid $= 0.9 gcm - 3, π = 3 = 0.9 gcm^{- 3}, π = 3$ ]
1. (1) $10^{- 6} m$
2. (2) $10^{- 8} m$
3. (3) $10^{- 2} m$
4. (4) $10^{- 4} m$
126.
The correct statement(s) pertiaining to the adsorption of a gas on a solid surface is (are)
1. (1) $Adsorption is always exothermic$
2. (2) $Physisorption may transform into chemisorption at high temperature$
3. (3) $Physisorption increases with increasing temperature but chemisorption decreases with increasing temperature$
4. (4) $Chemisorption is more exothermic than physisorption, however it is very slow due to higher energy of activation.$
127.
The Zeta potential is related to which property of colloids
1. (1) $Colour$
2. (2) $Tyndall effect$
3. (3) $Charge on the surface of colloidal particles$
4. (4) $Brownian movement$
128.
When a few typical solutes are separated by a particular selective membrane such as protein particles, blood corpuscles, this process is called
1. (1) $transpiration$
2. (2) $endosmosis$
3. (3) $dialysis$
4. (4) $diff usion.$
129.
Consider the reactions
I. $CO + 3 H_{2} \to A CH_{4} + H_{2} O$
II. $CO + 2 H_{2} \to B CH_{3} OH$
III. $O_{2} + 2 H_{2} \to C 2 H_{2} O$
The catalysts A, B, C are respectively
1. (1) $Ni, ZnO - Cr_{2} O_{3}, Pt$
2. (2) $Pt, ZnO - Cr_{2} O_{3}, Ni$
3. (3) $CuCl_{2}, Ni, V_{2} O_{5}$
4. (4) $Pd, Pt, ZnO - Cr_{2} O_{3}$
130.
For $As_{2} S_{3}$ sol, the most effective coagulating agent is
1. (1) $CaCO_{3}$
2. (2) $NaCl$
3. (3) $FeCl_{3}$
4. (4) $Clay$
131.
Which one of the following statement is not correct?
1. (1) $A mixture of dinitrogen and dioxygen at room temperature is an example for aerosol$
2. (2) $Lyophilic sols are more stable compared to lyophobic sols$
3. (3) $Formation of micelles is possible only above Kraft temperature$
4. (4) $An example for a soap is sodium stearate and an example for detergent is sodium lauryl sulphate$
132.
The volume of collodial particle $V_{C}$ as compared to the volume of a solute particle in a true solution $V_{S}$ could be:
1. (1) $\sim 1$
2. (2) $\sim 10^{23}$
3. (3) $\sim 10^{- 3}$
4. (4) $\sim 10^{3}$
133.
$10 g$ of a gas is adsorbed on $500 g$ of solid at $10 bar$ . If the pressure is increased at $20 bar, 14 g$ of the gas is adsorbed by the same solid at the same temperature. What is the slope of Freundlich adsorption isotherm?
1. (1) $1.0$
2. (2) $\frac{4}{3}$
3. (3) $3$
4. (4) $0.5$
134.
Amongst the following statements regarding adsorption, those that are valid are:
(A) Ali becomes less negative as adsorption proceeds
(B) On a given adsorbent, ammonia is adsorbed more than nitrogen gas
(C) On adsorption, the residual force acting along the surface of the adsorbent increases
(D) With increase in temperature, the equilibrium concentration of adsorbate increases
1. (1) $(C) and (D)$
2. (2) $(A) and (B)$
3. (3) $(D) and (A)$
4. (4) $(b) and (c)$
135.
Which of the following is not correctly matched for enzymatic reactions?
1. (1) $Proteins \to Amino acids ; Trypsin$
2. (2) $Starch \to Maltose; Diastase$
3. (3) $Sucrose \to glucose and fructose; zymase$
4. (4) $Maltose \to glucose; Maltase$
136.
Which of the following statements is incorrect regarding physissorptions?
1. (1) $More easily liquefiable gases are adsorbed readily.$
2. (2) $Under high pressure it results into multi molecular layer on adsorbent surface.$
3. (3) $Enthalpy of adsorption (Δ H_{adsorption}) is low and positive.$
4. (4) $It occurs because of van der Waal's forces.$
137.
In the reaction, $H_{2} O_{2 (aq)} \to I - (aq) H_{2} O_{(l)} + \frac{1}{2} O_{2 (g)}$ iodide ion acts as
1. (1) $homogeneous catalyst$
2. (2) $acid catalyst$
3. (3) $heterogeneous catalyst$
4. (4) $enzyme catalyst.$
138.
Which of the following is an example of homogeneous catalysis?
1. (1) $Oxidation of NH_{3} in Ostwald's process$
2. (2) $Oxidation of SO_{2} in contact process$
3. (3) $Oxidation of SO_{2} in lead chamber process$
4. (4) $Manufacture of NH_{3} by Haber's process$
139.
Which one of the following is used in the hardening of leather?
1. (1) $Light sensitive silver bromide in gelatin$
2. (2) $Sodium lauryl sulphate$
3. (3) $Alum$
4. (4) $Tannin$
140.
The correct option among the following is:
1. (1) $Colloidal medicines are more effective because they have small surface area$
2. (2) $Addition of alum of water makes it unit for drinking$
3. (3) $Colloidalparticles in lyophobic sols can be precipitated by electrophoresis$
4. (4) $Brownian motion in colloidal solution is faster the viscosity of the solution is very high.$
141.
$Match List-I with List-II$
$List-I$ $List-II$
$(A) Lyophilic colloid$ $(I) Liquid-liquid colloid$
$(B) Emulsion$ $(II) protective colloid$
$(C) Positively charged$ $(III) F e C l_{3} + NaOH$
$(D) Negatively charged$ $(IV) F e C l_{3} + hot water colloid$
$Choose the correct answer from the options given below:$
1. (1) $(A) - (II), (B) - (I), (C) - (IV), (D) - (III)$
2. (2) $(A) - (III), (B) - (I), (C) - (IV), (D) - (II)$
3. (3) $(A) - (II), (B) - (I), (C) - (III), (D) - (IV)$
4. (4) $(A) - (III), (B) - (II), (C) - (I), (D) - (IV)$
142.
A plot of $\frac{1}{T} vsk$ for a reaction gives the slope $- 1 \times 10^{4} K$ . The energy of activation for the reaction is (Given : $R = 8.314 J K^{- 1} mol^{- 1}$ )
1. (1) $8314 J mol^{- 1}$
2. (2) $1.202 kJ mol^{- 1}$
3. (3) $12.02 J mol^{- 1}$
4. (4) $83.14 kJ mol^{- 1}$
143.
The ability of anion, to bring about coagulation of a given colloid, depends upon
1. (1) $magnitude of the charge$
2. (2) $both magnitude and charge$
3. (3) $its charge only$
4. (4) $sign of the charge alone.$
144.
The auto catalyst in the redox reaction involving acidified potassium permanganate and oxalic acid is
1. (1) $Mn^{2 +}$
2. (2) $SO_{4}^{2 -}$
3. (3) $CO_{2}$
4. (4) $H_{2} O$
145.
Most suitable salt which can be used for efficient clotting of blood will be :
1. (1) $Mg (HC O_{3})_{2}$
2. (2) $FeS O_{4}$
3. (3) $NaHC O_{3}$
4. (4) $FeC l_{3}$
146.
The aerosol is a kind of colloid in which:
1. (1) $solid is dispersed in gas$
2. (2) $gas is dispersed in solid$
3. (3) $gas is dispersed in liquid$
4. (4) $liquid is dispersed in water$
147.
Identify the factors which favour the physical adsorption from the following.
(I) High surface area
(II) Low temperatures
(III)High temperatures
(IV) Low pressures
(V) High pressures
1. (1) $I, III & IV only$
2. (2) $I, II & V only$
3. (3) $III & V only$
4. (4) $I, II & IV only$
148.
$Coagulating value of the electrolytes AlCl_{3} and NaCl for As_{2} S_{3} are 0.09 and 50.04 respectively. The coagulating power of AlCl_{3} is x times the coagulating power of NaCl. The value of x is .$
149.
$For Freundlich adsorption isotherm, a plot of log (\frac{x}{m}) (y - aixs) and log p (x - axis) gives a straight line. The intercept and slope for the line is 0.4771 and 2, respectively. The mass of gas, adsorbed per gram of adsorbent if the initial pressure is 0.04 atm, is \times 10^{- 4} g (log 3 = 0.4771) .$
150.
$The number of statement/s which are the characteristics of physisorption is___________. A. It is highly specific in nature B. Enthalpy of adsorption is high C It decreases with increase in temperature D. It results into unimolecular layer E. No activation energy is needed$