iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 20th July Morning Shift
The conditions given below are in the context of observing Tyndall effect in colloidal solutions :
(A) The diameter of the colloidal particles is comparable to the wavelength of light used.
(B) The diameter of the colloidal particles is much smaller than the wavelength of light used.
(C) The diameter of the colloidal particles is much larger than the wavelength of light used.
(D) The refractive indices of the dispersed phase and the dispersion medium are comparable.
(E) The dispersed phase has a very different refractive index from the dispersion medium.
Choose the most appropriate conditions from the options given below :
A.
(A) and (E) only
B.
(C) and (D) only
C.
(A) and (D) only
D.
(B) and (E) only
Correct Answer: A
Explanation:
The phenomenon of scattering of light by colloidal particles as a result of which the path of the
beam becomes visible is called a tyndall effect. Smaller the diameter and similar the magnitude
of refractive indices, lesser is the scattering and hence the tyndall effect and viced-versa. The
diameter of the dispersed phase particle should not be smaller than the wavelength of light
used because they won't be able to scatter the light so, therefore, the diameter of the dispersed
particles should be equal or not much smaller than the wavelength of the light used.
2. The refractive indies (i.e. the ratio of the velocity of light in vacuum to the velocity of light in
any medium) of the dispersed phase and the dispersion medium should differ greatly
in magnitude than only the particles will be able to scatter the light and tyndall effect will be
obersved. On the other hand, if the refractive indices of the dispersed phase and dispersion
medium are almost similar in magnitude, then there will be no-scattering of light and hence,
therefore, no Tyndall effect effect is observed.
Hence answer (A) and (E) are correct.
2021
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 18th March Evening Shift
The charges on the colloidal CdS sol and TiO2 sol are, respectively :
A.
positive and positive
B.
positive and negative
C.
negative and negative
D.
negative and positive
Correct Answer: D
Explanation:
Oxides & Hydroxide sol are positive
so TiO2 is positive sol.
Sulphide sol are negatively charge
so CdS is negatively charge sol.
2021
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 17th March Evening Shift
For the coagulation of a negative sol, the species below, that has the highest flocculating power is :
A.
Na+
B.
Ba2+
C.
PO$_4^{3 - }$
D.
SO$_4^{2 - }$
Correct Answer: B
Explanation:
For a negative sol, a positive ion is required for flocculation.
The greater the valence of the flocculating ion added, the greater is its power to cause
precipitation. This is called Hardy-Schulz law.
So, Ba+2 has highest flocculating power.
2021
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 17th March Morning Shift
A colloidal system consisting of a gas dispersed in a solid is called a/an :
A.
foam
B.
aerosol
C.
solid sol
D.
gel
Correct Answer: C
Explanation:
A colloidal system consisting of a gas dispersed in
a solid is called a ‘solid sol’.
2021
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 16th March Evening Shift
The INCORRECT statements below regarding colloidal solutions is :
A.
The flocculating power of Al3+ is more than that of Na+.
B.
A colloidal solutions shows Brownian motion of colloidal particles.
C.
An ordinary filter paper can stop the flow of colloidal particles.
D.
A colloidal solutions shows colligative properties.
Correct Answer: C
Explanation:
Colloidal solutions can pass through ordinary filter paper but cannot pass through a special filter colloidal solution coated paper.
2021
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 26th February Evening Shift
The nature of charge on resulting colloidal particles when FeCl3 is added to excess of hot water is :
A.
neutral
B.
sometimes positive and sometimes negative
C.
positive
D.
negative
Correct Answer: C
Explanation:
If FeCl3 is added to excess of hot water, a positively charged sol of hydrated ferric oxide is
formed due to adsorption of Fe3+ ions.
2021
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 25th February Evening Shift
Which one of the following statements is FALSE for hydrophilic sols?
A.
They do not require electrolytes for stability.
B.
The sols cannot be easily coagulated.
C.
These sols are reversible in nature.
D.
Their viscosity is of the order of that of H2O.
Correct Answer: D
Explanation:
1. Viscosity of hydrophilic sol > viscosity of H2O
2. Hydrophilic sol is more stable so can't be
easily coagulated.
3. Hydrophilic sols are reversible sols.
4. No electrolytes are required to stabilise
hydrophilic sol.
2021
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 25th February Morning Shift
In Freundlich adsorption isotherm at moderate pressure, the extent of adsorption $\left( {{x \over m}} \right)$ is directly proportional to Px. The value of x is :
A.
$\infty $
B.
zero
C.
1
D.
${{1 \over n}}$
Correct Answer: D
Explanation:
According to Freundlich adsorption isotherm, in the median range of pressure
For straight line, comparing above equation to y = mx + c
So, m = slope = ${1 \over n}$
Hence 0 $ \le $ ${1 \over n}$ $ \le $ 1
It value lies in between 0 to 1.
2021
JEE Mains
Numerical
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 31st August Evening Shift
CH4 is absorbed on 1g charcoal at 0$^\circ$C following the Freundlich adsorpiton isotherm 10.0 mL of CH4 is adsorbed at 100 mm of Hg, whereas 15.0 mL is adsorbed at 200 mm of Hg. The volume of CH4 adsorbed at 300 mm of Hg is 10x mL. The value of x is _________ $\times$ 10-2.
$\Rightarrow$ x = 128 $\times$ 10$-$2 (Nearest integer)
2021
JEE Mains
Numerical
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 27th July Morning Shift
CO2 gas adsorbs on charcoal following Freundlich adsorption isotherm. For a given amount of charcoal, the mass of CO2 adsorbed becomes 64 times when the pressure of CO2 is doubled. The value of n in the Freundlich isotherm equation is ____________ $\times$ 10$-$2. (Round off to the Nearest Integer)
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 20th July Evening Shift
100 ml of 0.0018% (w/v) solution of Cl$-$ ion was the minimum concentration of Cl$-$ required to precipitate a negative sol in one h. The coagulating value of Cl$-$ ion is _________ (Nearest integer)
Correct Answer: 1
Explanation:
Coagulation value The minimum concentration of electrolyte in millimoles required to cause coagulation of 1 L of colloidal solution.
Given, 0.0018 g Cl$-$ present in 100 mL solution
Coagulation value of Cl$-$ is $ = {{{{0.0018} \over {35.5}} \times {{10}^3}} \over {0.1}} = 0.5070 \simeq 1$
2020
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 6th September Morning Slot
Kraft temperature is the temperature :
A.
below which the aqueous solution of
detergents starts freezing.
B.
above which the formation of micelles takes
place.
C.
below which the formation of micelles takes
place.
D.
above which the aqueous solution of
detergents starts boiling.
Correct Answer: B
Explanation:
Above Kraft temperature(Tk) the formation of
micelles takes place.
2020
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 5th September Evening Slot
Adsorption of a gas follows Freundlich adsorption isotherm. If x is the mass of the gas adsorbed
on mass m of the adsorbent, the correct plot of ${x \over m}$ versus p is :
A.
B.
C.
D.
Correct Answer: B
Explanation:
Freundlich adsorption isotherm
${x \over m} = K{p^{{1 \over n}}}$
With increase in temperature, decrease in
physical adsorption is observed.
${x \over m}$ v/s ${p^{{1 \over n}}}$ is non linear curve.
2020
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 5th September Morning Slot
Identify the correct molecular picture showing
that happens at the critical micellar
concentration (CMC) of an aqueous solution of
a surfactant ( ◍ polar head; ∼ non-polar tail;
● water).
A.
(C)
B.
(A)
C.
(D)
D.
(B)
Correct Answer: C
Explanation:
At CMC, micelle formation takes place.
2020
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 4th September Evening Slot
A sample of red ink (a colloidal suspension) is
prepared by mixing eosin dye, egg white, HCHO
and water. The component which ensures
stability of the ink sample is :
A.
HCHO
B.
Water
C.
Eosin dye
D.
Egg white
Correct Answer: D
Explanation:
Egg white is used to stabilise the prepared
colloidal sol.of red ink.
2020
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 4th September Morning Slot
Match the following :
(i) Foam
(a) smoke
(ii) Gel
(b) cell fluid
(iii) Aerosol
(c) jellies
(iv) Emulsion
(d) rubber
(e) froth
(f) Milk
A.
(i)-(e), (ii)-(c), (iii)-(a), (iv)-(f)
B.
(i)-(d), (ii)-(b), (iii)-(a), (iv)-(e)
C.
(i)-(d), (ii)-(b), (iii)-(e), (iv)-(f)
D.
(i)-(b), (ii)-(c), (iii)-(e), (iv)-(d)
Correct Answer: A
Explanation:
Foam $ \to $ Froth, whipped cream, soaplather
Gel $ \to $ Cheese, butter, jellies
Aerosol $ \to $ smoke dust
Emulsion $ \to $ milk
2020
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 3rd September Evening Slot
An ionic micelle is formed on the addition of :
A.
excess water to liquid
B.
excess water to liquid
C.
liquid diethyl ether to aqueous NaCl solution
D.
sodium stearate to pure toluene
Correct Answer: A
Explanation:
Ionic micelles formed by addition of water to soap {sodium stearate}.
2020
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 3rd September Morning Slot
Tyndall effect is observed when:
A.
The diameter of dispersed particles is similar to the wavelenght of light used.
B.
The diameter of dispersed particles is much smaller than the wavelength of light used.
C.
The diameter of dispersed particles is much larger than the wavelength of light used.
D.
The refractive index of dispersed phase is greater than that of the dispersion medium.
Correct Answer: A
Explanation:
Diameter of dispersed particles should not be much smaller than wavelength of light used.
2020
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 2nd September Evening Slot
Amongst the following statements regarding
adsorption, those that are valid are
(a) $\Delta $H 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
A.
(c) and (d)
B.
(a) and (b)
C.
(d) and (a)
D.
(b) and (c)
Correct Answer: B
Explanation:
(a) Since adsorption is exothermic process, as adsorption proceeds number of active sites present over
adsorbent decreases, so less heat is evolved.
(b) Since NH3 has higher force of attraction on adsorbent due to its polar nature.
(c) As the adsorption increases, residual forces over surface decreases.
(d) Since process is exothermic, on increasing temperature it shift to backward direction, so concentration of
adsorbate particle decreases.
2020
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 2nd September Morning Slot
Which of the following is used for the
preparation of colloids?
A.
Van Arkel Method
B.
Bredig’s Arc Method
C.
Mond Process
D.
Ostwald Process
Correct Answer: B
Explanation:
Bredig's arc method is used for the preparation
of colloids.
2020
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 9th January Evening Slot
A mixture of gases O2, H2 and CO are taken in
a closed vessel containing charcoal. The graph
that represents the correct behaviour of
pressure with time is :
A.
B.
C.
D.
Correct Answer: C
Explanation:
Initially H2 combines with O2, therefore rapid
fall in pressure will be observed. Then
gradually adsorption of CO will occur by
activated charcoal.
2020
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 8th January Evening Slot
For the following Assertion and Reason, the
correct option is Assertion : For hydrogenation reactions, the
catalytic activity increases from Group 5 to
Group 11 metals with maximum activity shown
by Group 7-9 elements. Reason : The reactants are most strongly
adsorbed on group 7-9 elements.
A.
Both assertion and reason are true and
the reason is the correct explanation for
the assertion.
B.
The assertion is true, but the reason is false.
C.
Both assertion and reason are true but the
reason is not the correct explanation for the
assertion.
D.
Both assertion and reason are false.
Correct Answer: B
Explanation:
Reactants must not get adsorbed so strongly
that they are immobilised and other reactants
are left with no space on the catalyst’s surface
for adsorption.
2020
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 8th January Morning Slot
As per Hardy-Schulze formulation, the flocculation values of the following for ferric hydroxide sol are in the
order :
A.
AICl3 > K3[Fe(CN)6] > K2CrO4 > KBr = KNO3
B.
K3[Fe(CN)6] < K2CrO4 < KBr = KNO3 = AlCl3
C.
K3[Fe(CN)6] < K2CrO4 < AlCl3 < KBr < KNO3
D.
K3[Fe(CN)6] > AlCl3 > K2CrO4 > KBr > KNO3
Correct Answer: B
Explanation:
Since, Fe(OH)3 is positively charged sol, hence,
anionic charge will flocculate.
As per Hardy Schulze rules coagulation power
of anion follows the order :
Fe(CN)63– $>$ CrO42– $>$ Cl– = Br– = NO3–
Higher the coagulation power lower will be its
flocculation value
therefore order will be :
Fe(CN)63– $<$ CrO42– $<$ Cl– = Br– = NO3–
2020
JEE Mains
Numerical
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 6th September Evening Slot
For Freundlich adsorption isotherm, a plot of
log (x/m) (y-axis) 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)
Correct Answer: 48
Explanation:
According to Freundlich adsorption isotherm, in the median range of pressure
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 2nd September Morning Slot
The mass of gas adsorbed, x, per unit mass of
adsorbate, m, was measured at various pressures,
p. A graph between $\log {x \over m}$
and log p gives a
straight line with slope equal to 2 and the intercept
equal to 0.4771. The value of
${x \over m}$
at a pressure of
4 atm is :
(Given log 3 = 0.4771)
Correct Answer: 48
Explanation:
According to Freundlich adsorption isotherm, in the median range of pressure
Here in graph between log${x \over m}$ and logP,
slope is ${1 \over n}$ and intercepts = log k.
Given, log k = 0.4771 $ \Rightarrow $ k = 3
Slope ${1 \over n}$ = 2
put in eq. (1), ${x \over m}$ = 3 $ \times $ (4)2 = 48
2019
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2019 (Online) 12th April Evening Slot
Among the following, the INCORRECT statement about colloids is :
A.
The range of diameters of colloidal particles is between 1 and to 1000 nm
B.
they are larger than small molecules and have high molar mass
C.
They can scatter light
D.
The osmotic pressure of a colloidal solution is of higher order than the true solution at the same
concentration.
Correct Answer: D
Explanation:
Osmotic pressure of colloidal solution is lower than true solution of same concentration.
2019
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2019 (Online) 12th April Morning Slot
Peptization is a :
A.
process of converting soluble particles to form colloidal solution
B.
process of converting precipitate into colloidal solution
C.
process of bringing colloidal molecule into solution
D.
process of converting a colloidal solution into precipitate
Correct Answer: B
Explanation:
Peptisation is the process of converting a
precipitate into a colloidal solution by shaking it with
dispersion medium in the presence of small
amount of electrolyte.
2019
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2019 (Online) 10th April Evening Slot
The correct option among the following is :
A.
Addition of alum to water makes it unfit for drinking.
B.
Colloidal medicines are more effective because they have small surface area.
C.
Colloidal paraticles in lyophobic sols can be precipitated by electrophoresis.
D.
Brownian motion in colloidal solution is faster if the viscosity of the solution is very high.
Correct Answer: C
Explanation:
Electrophoresis is used to coagulate lyophobic
colloids.
2019
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2019 (Online) 10th April Morning Slot
A gas undergoes physical adsorption on a surface and follows the given Freundlich adsorption isotherm equation
${x \over m} = k{p^{0.5}}$
Adsorption of the gas increase with :
A.
Decrease in p and increase in T
B.
Increase in p and decrease in T
C.
Decrease in p and decrease in T
D.
Increase in p and increase in T
Correct Answer: B
Explanation:
Physical adsorption increases with
increase of pressure and decrease of
temperature.
2019
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2019 (Online) 9th April Morning Slot
Match the catalysts (Column I) with products
(Column II).
Column I
Column II
(A) V2O5
(i) Polyethylene
(B) TiCl4/Al(Me)3
(ii) ethanal
(C) PdCl2
(iii) H2SO4
(D) Iron Oxide
(iv) NH3
A.
(A)-(iii); (B)-(i); (C)-(ii); (D)-(iv)
B.
(A)-(ii); (B)-(iii); (C)-(i); (D)-(iv)
C.
(A)-(iii); (B)-(iv); (C)-(i); (D)-(ii)
D.
(A)-(iv); (B)-(iii); (C)-(ii); (D)-(i)
Correct Answer: A
Explanation:
(A) V2O5 is used for preparation of H2SO4 in
contacts process.
(B) TiCl4 + Al(Me)3 this mixture is called Ziegler-Natta catalyst which is used in the synthesis of high density polyethene from ethene.
(C) PdCl2 is used in ethanol formation
(D) Iron oxide is used in Haber process for NH3.
2019
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2019 (Online) 9th April Morning Slot
The aerosol is a kind of colloid in which :
A.
solid is dispersed in gas
B.
gas is dispersed in solid
C.
gas is dispersed in liquid
D.
liquid is dispersed in water
Correct Answer: A
Explanation:
In aerosol, the dispersion medium is gas while
the dispersed phase can be both solid or liquid.
2019
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2019 (Online) 8th April Morning Slot
Adsorption of a gas follows freundlich adosorbed isotherm. x is the mass of the gas adsorbed on
mass m of the adsorbent. The plot log $x \over m$ versus log p is shown in the given graph. $x \over m$ is
proportional to :
A.
p2/3
B.
p3
C.
p2
D.
p3/2
Correct Answer: A
Explanation:
According to Freundlich adsorption isotherm, in the median range of pressure
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2019 (Online) 12th January Evening Slot
Among the following the false statement is -
A.
Lyophilic sol can be coagulated by adding an electrote
B.
Tyndall effect can be used to distinguish between a colloidal solution and a true solution
C.
It is possible to cause artificial rain by throwing electrified sand carrying charge opposite to the one on clouds from an aeroplane
D.
Latex is a colloidal solution of rubber particles which are positively charged
Correct Answer: D
Explanation:
Latex is a colloidal solution of rubber particles which are negatively charged.
2019
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2019 (Online) 12th January Morning Slot
Given
Gas
H2
CH4
CO2
SO2
Critical
Temperature / K
33
190
304
630
On the basis of data given above, predict which of the following gases shows least adsorption on a definite amount of charcoal ?
A.
SO2
B.
CH4
C.
H2
D.
CO2
Correct Answer: C
Explanation:
Adsorption $ \propto $ Tc
Therefore, H2
gas shows least adsorption on a definite amount
of charcoal.
2019
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2019 (Online) 11th January Evening Slot
Among the colloids cheese (C), milk (M), and smoke (S), the correct combination of the dispersed phase and dispersion medium, respectively is :
A.
C : liquid in solid ; M : liquid in liquid ; S : solid in gas
B.
C : liquid in solid ; M : liquid in solid ; S : solid in gas
C.
C : solid in liquid ; M : liquid in liquid ; S : gas in solid
D.
C : solid in liqid ; M : solid in liquid ; S : solid in gas
Correct Answer: A
Explanation:
Cheese (C) is liquid dispersed in solid.
Milk (M) is liquid dispersed in liquid.
Smoke (S) is solid dispersed in gas.
2019
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2019 (Online) 11th January Morning Slot
An example of solid sol is :
A.
Butter
B.
Hair cream
C.
Gem stones
D.
Paint
Correct Answer: C
Explanation:
An example of solid sol is gem stones.
2019
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2019 (Online) 10th January Evening Slot
Haemoglobin and gold sol are examples of :
A.
positively charged sols
B.
negatively charged sols
C.
Positively and negatively charged sols, respectively
D.
negatively and positively charged sols, respectively
Correct Answer: C
Explanation:
Haemoglobin $\buildrel \, \over
\longrightarrow $ positive sol
Ag $-$ sol $\buildrel \, \over
\longrightarrow $ negative sol
2019
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2019 (Online) 10th January Morning Slot
Which of the following is not an example of heterogenous catalytic reaction?
A.
Ostwald's process
B.
Combustion of coal
C.
Hydrogenation of vegetable oils
D.
Haber's process
Correct Answer: B
Explanation:
Then is no catalyst is required for combustion of coal.
2019
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2019 (Online) 9th January Evening Slot
For coagulation of arsenious sulphate sol, which one of the following salt solution will be most effective ?
A.
BaCl2
B.
AlCl3
C.
NaCl
D.
Na3PO4
Correct Answer: B
Explanation:
Sulphide is $-$ve charged colloid.
As coagulation is directly proportional to the effective charge, so cation with maximum charge will be most effective for coagulation.
Al3+ > Ba2+ > Na+ coagulating power.
2019
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2019 (Online) 9th January Morning Slot
Adsorption of a gas follows Freundlich adsorption isotherm. In the given plot, x is the mass of the gas adsorbed on mass m of the adsorbent at pressure P. ${x \over m}$ is proportional to :
A.
P2
B.
P${^{{1 \over 4}}}$
C.
P${^{{1 \over 2}}}$
D.
P
Correct Answer: C
Explanation:
According to Freundlich adsorption isotherm, in the median range of pressure
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2018 (Online) 16th April Morning Slot
Which one of the following is not a property of physical adsorption?
A.
Higher the pressure, mre the adsorption
B.
Lower the temperature, more the adsorption
C.
Greater the surface area, more the adsorption
D.
Unilayer adsorption ocurs
Correct Answer: D
Explanation:
Physical absorption increases with increase in pressure and decreases with increases in temperature.
When surface are increases then physical absorption also increases.
Physical absorption can perform multiple layer of absorption.
2018
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2018 (Online) 15th April Evening Slot
If x gram of gas is adsorbed by m gram of adsorbent at pressure P, the plot of log ${x \over m}$ versus log P is linear. The slope of the plot is :
(n and k are constants and n > 1)
A.
2 k
B.
log k
C.
n
D.
${1 \over n}$
Correct Answer: D
Explanation:
According to Freundlich adsorption isotherm, in the median range of pressure
Here in graph between log${x \over m}$ and logP,
slope is ${1 \over n}$ and intercepts = log k.
2018
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2018 (Online) 15th April Morning Slot
Which of the following statements about colloids is False ?
A.
Freezing point of colloidal solution is lower than true solution at same concentration of a solute.
B.
Colloidal particles can pass through ordinary filter paper.
C.
When silver nitrate solution is added to potassium iodide solution, a negatively charged colloidal solution is formed.
D.
When excess of electolyte is added to colloidal solution, colloidal particle will be precipitated.
Correct Answer: A
Explanation:
Freezing point of colloidal solution is same as true solution at same concentration of a solute.
2017
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2017 (Online) 9th April Morning Slot
Adsorption of a gas on a surface follows Freundlich adsorption isotherm. Plot of
log ${x \over m}$ versus log p gives a straight line with slope equal to 0.5, then:
( ${x \over m}$ is the mass of the gas adsorbed per gram of adsorbent)
A.
Adsorption is independent of pressure.
B.
Adsorption is proportional to the pressure.
C.
Adsorption is proportional to the square root of pressure.
D.
Adsorption is proportional to the square of pressure.
Correct Answer: C
Explanation:
According to Freundlich adsorption isotherm, in the median range of pressure
$ \therefore $ Adsorption is proportional to the square root of pressure.
2017
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2017 (Online) 8th April Morning Slot
Among the following, correct statement is :
A.
Brownian movement is more pronounced for smaller particles than for bigger–particles
B.
Sols of metal sulphides are lyophilic.
C.
Hardy Schulze law states that bigger the size of the ions, the greater is its
coagulating power.
D.
One would expect charcoal to adsorb chlorine more than hydrogen sulphide.
Correct Answer: D
Explanation:
(a) Brownian motion caused by the bombardment of the particles by molecules of the median. In smaller particle the bombardment is not effective enough so that it can change it's direction and perform zig zag motion. But for bigger particle zig zag motion happens as bombardment is effective.
(b) Inorganic sols are lyophobic. Metal sulphates are inorganic sols so it is lyophotic.
(c) Hardly Schulze does not depends on the size of the ion it depends on the size of the ion it depends on the charge on the ion.
(d) Molar mass of Cl2 is 71 and molar mass of H2S is 34 and in both the molecule Nanderwaal force of attraction present. As Cl2 has more mass than H2S So it's vanderwall force of attraction will be more and tendency to melt will also be more. So, Cl2 will get easily absorbed.
