Chapter Questions
The size of particles in suspension, true solution and colloidal solution varies in the order :(a) suspension > colloidal > true solution(b) true solution $>$ suspension $>$ colloidal(c) suspension $>$ colloidal $=$ true solution(d) none of these
A colloidal system has what size of particles?(a) $10^{-4} \mathrm{~m}$ to $10^{-10} \mathrm{~m}$(b) $10^{-5} \mathrm{~m}$ to $10^{-7} \mathrm{~m}$(c) $10^{-9} \mathrm{~m}$ to $10^{-12} \mathrm{~m}$(d) $10^{-6} \mathrm{~m}$ to $10^{-9} \mathrm{~m}$
Which are not purely surface phenomena?(a) - Adsorption, surface tension(b) Surface tension, viscosity(c) Adsorption, viscosity(d) Absorption, viscosity
Adsorbed acetic acid on activated carbon is :(a) adsorber(b) absorber(c) adsorbent(d) adsorbate
Adsorption due to strong chemical forces is called :(a) Chemisorption(b) Physisorption(c) Both (a) and (b)(d) None of these
Adsorption of gases on solid surface is exothermic because :(a) free energy increases(b) entropy decreases(c) entropy increases(d) interaction developed between gas and solid particles
The nature of bonding forces in adsorption are:(a) purely physical such as van der Waals' forces(b) purely chemical(c) both chemical and physical are possible(d) none of these
Which one of the following is not applicable to chemisorption?(a) Heat of adsorption is negative(b) It takes place at high temperature(c) It is reversible(d) It forms mono-molecular layer
Which of the following statement is not correct?(a) Physical adsorption is due to vander Waals' forces(b) Physical adsorption is irreversible
Which gas will be adsorbed on a solid to greater extent?(a) Having non-polar molecule(b) Having highest critical temperature(c) Having lowest critical temperature(d) Having lowest critical pressure
Which of the following factors affects the adsorption of a gas on solid?(a) Critical temperature $\left(T_{c}\right)$(b) Temperature of gas(c) Pressure of gas(d) All of these
Which gas is adsorbed to maximum amount by activated carbon?(a) $\mathrm{H}_{2}(\mathrm{~g})$(b) $\mathrm{He}(\mathrm{g})$(c) $\mathrm{CO}(\mathrm{g})$(d) $\mathrm{CO}_{2}(\mathrm{~g})$
The volume of gases $\mathrm{NH}_{3}, \mathrm{CO}_{2}$ and $\mathrm{H}_{2}$ adsorbed by one gram of charcoal at $300 \mathrm{~K}$ are in order of:(a) $\mathrm{H}_{2}>\mathrm{CO}_{2}>\mathrm{NH}_{3}$(b) $\mathrm{NH}_{3}>\mathrm{H}_{2}>\mathrm{CO}_{2}$(c) $\mathrm{NH}_{3}>\mathrm{CO}_{2}>\mathrm{H}_{2}$(d) $\mathrm{CO}_{2}>\mathrm{NH}_{3}>\mathrm{H}_{2}$
Which of the following is used to adsorb water?(a) Silica gel(b) Calcium acetate(c) Hair gel(d) Anhydrous $\mathrm{CaCl}_{2}$
Absorption and adsorptions are respectively:(a) surface phenomena, bulk phenomena(b) bulk phenomena, surface phenomena(c) both are bulk phenomena(d) both are surface phenomena
Adsorption is multilayer in case of:(a) physical adsorption(b) chemisorption(c) both (a) and (b)(d) none of these
Reversible adsorption is:(a) chemical adsorptioin(b) physical adsorption(c) both (a) and (b)(d) none of these
The effect of pressure on adsorption is high if:(a) temperature is low(b) temperature is high(c) temperature is very high(d) larger charcoal piece is taken
Sorption is the phenomenon:(a) reverse of adsorption(b) reverse of absorption(c) when adsorption and absorption takes place simultaneously(d) none of these
Which of the following adsorption isotherms represents the adsorption of a gas by a solid involving multilayers of layers? $\left(P_{s}=\right.$ saturation pressure)
A plot of $\log \left(\frac{x}{M}\right)$ against $\log P$ for the adsorption of a gas on a solid gives a straight line with slope equal to:(a) $\frac{1}{n}$(b) $n$(c) $\log \mathrm{K}$(d) $\mathrm{K}$
The heat evolved in chemisorption lies in the range (in $\mathrm{kJ} / \mathrm{mol}$ ) of :(a) 80 to 240(b) 20 to 40(c) 40 to 80(d) 20 to 100
The heat evolved in physisorption lies in the range (in $\mathrm{kJ} / \mathrm{mol}$ ) of :(a) $20-40$(b) $40-100$(c) $100-200$(d) $200-400$
According to the adsorption theory of catalysis, the speed of the reaction increases because :(a) in the process of adsorption, the activation energy of the molecules becomes large(b) adsorption produces heat which increases the speed of the reaction(c) adsorption lowers the activation energy of the reaction(d) adsorption increases the activation energy of the reaction
$3.6$ gram of oxygen is adsorbed on $1.2 \mathrm{~g}$ of metal powder. What volume of oxygen adsorbed per gram of the adsorbent at 1 atm and $273 \mathrm{~K}$ ?(A) $0.19 \mathrm{Lg}^{-1}$(b) $1 \mathrm{Lg}^{-1}$(C) $2.1 \mathrm{Lg}^{-1}$(d) None of these
A catalytic poison renders the catalyst ineffective because:(a) It is preferentially adsorbed on the catalyst(b) It adsorbs the molecules of the reactants(c) It combines chemically with the catalyst(d) It combines chemically with one of the reactants
The catalyst used in the hydrogenation of oils is:(a) $\mathrm{Fe}$(b) Ni(c) $\mathrm{Pt}$(d) $\mathrm{V}_{2} \mathrm{O}_{5}$
The function of zymase is to:(a) Change starch into sugar(b) Ferment glucose to alcohol and $\mathrm{CO}_{2}$(c) Change malt sugar into glucose(d) Change starch into malt sugar and dextrin
The conversion of maltose to glucose is possible by the enzyme:(a) Zymase(b) Lactase(c) Maltase(d) Diastase
Shape selective catalysis is a reaction catalysed by:(a) Enzymes(b) Ziegler-Natta Catalyst(c) Zeolites(d) Platinum
The process which is catalysed by one of the product is called:(a) acid-base catalysis(b) autocatalysis(c) negative catalysis(d) homogeneous catalysis
An inhibitor is essentially:(a) a negative catalyst(b) a heterogeneous catalyst(c) an auto catalyst.(d) a homogeneous catalyst
A catalyst in the finely divided form is most effective because:(a) less surface area is available(b) more active sites are formed(c) more energy gets stored in the catalyst(d) none of these
Identify the correct statement regarding enzymes:(a) Enzymes are specific biological catalysts that normally works at high temperature(b) Enzymes are normally heterogeneous catalysts decreases reaction rate(c) Enzymes are specific biological catalysts with low molar masses(d) Enzymes are specific biological catalysts that are very specific in nature
A liquid leaves no residue when passed through the ultra-filter paper. The liquid is:(a) a suspension(b) oil(c) a colloidal sol(d) a true solution
Crystalloids differ from colloids mainly in respect of :(a) Electrical behaviour(b) Particle nature(c) Particle size(d) Solubility
Surface tension of lyophilic sols is:(a) lower than water(b) more than water(c) equal to water(d) none of these
Which one of the following is not used for preparing lyophilic sols?(a) Starch(b) Gum(c) Gelatin(d) Metal sulphide
Which one of the sols acts as protective colloid?(a) $\mathrm{As}_{2} \mathrm{~S}_{3}$(b) Gelatin(c) Au(d) $\mathrm{Fe}(\mathrm{OH})_{3}$
Which one of the following is lyophilic colloid?(a) $\mathrm{Pt}$(b) Gum(c) Fog(d) Blood
Small liquid droplets dispersed in another liquid is called:(a) suspension(b) emulsion(c) gel(d) true solution
Which of the following is an example of associated colloid?(a) Protein in water(b) Soap in water(c) Rubber in benzene(d) $\mathrm{FeCl}_{3}$ in $\mathrm{H}_{2} \mathrm{O}$
Select the properties which are for lyophilic colloidal sols:(a) viscosity same as that of the medium(b) extensive hydration takes place(c) particles migrate either towards cathode or anode in an electric field(d) particle cannot be detected even under ultramicroscope
Fog is an example of colloidal system of:(a) liquid in a gas(b) gas in a liquid(c) gas in a solid(d) solid in a liquid
Colloidal solutions are not classified on the basis of :(a) molecular size(b) nature of the particles(c) surface tension value(d) interaction between disperse phase and dispersion medium
All colloids:(a) are suspensions of one phase in another(b) are two-phase systems(c) contain only water-soluble particles(d) are true solutions
Which of the following is a lyophobic colloid?(a) Gelatin(b) Sulphur(c) Starch(d) Gum arabic
Which of the following is not a gel?(a) Cheese(b) Jellies(c) Curd(d) Mitk
Cleaning action of soap occurs because:(a) non-polar tails of soap molecules dissolve in grease(b) oil and grease dissolved into hydrophilic centres of soap micelles acid washed away(c) hydrophilic head dissolve in grease(d) grease dissolve in soap solution
Arsenous sulphide sol is prepared by passing $\mathrm{H}_{2} \mathrm{~S}$ through arsenous oxide solution. The charge developed on the particies is due to adsorption of:(a) $\mathrm{H}^{+}$(b) $\mathrm{S}^{2-}$(c) $\mathrm{OH}^{-}$(d) $\mathrm{O}^{2-}$
Bredig's arc method cannot be used for the preparation of colloidal sol of :(a) copper(b) gold(c) silver(d) sodium
$\mathrm{As}_{2} \mathrm{~S}_{3}$ sol is:(a) positive colloid(b) negative colloid(c) neutral colloid(d) none of the above
Which of the following electrolyte will be most effective in coagulation of negative sol?(A) $\mathrm{KNO}_{3}$(b) $\mathrm{K}_{4}\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]$(C) $\mathrm{Na}_{3} \mathrm{PO}_{4}$(d) $\mathrm{MgCl}_{2}$
The minimum amount of an electrolyte required to cause coagulation of a sol is called:(a) Coagulation value(b) Gold number(c) Protective value(d) None of these
The electrical charge on a colloidal particle is indicated by:(a) Brownian movement(b) electrophoresis(c) ultramicroscope(d) molecular sieves
Colloidal particles in a sol can be coagulated by:(a) heating(b) adding an electrolyte(c) adding oppositely charged sol(d) any of the above methods
Peptization involves:(a) precipitation of colloidal particles(b) disintegration of colloidal aggregates(c) purification of colloids(d) impact of molecules of the dispersion medium on the colloidal particles
Hardy-Schulze law states that:(a) solution must have higher gold number(b) disperse phase and dispersion medium must be of the same sign(c) micelles coagúlate in presence of surfactants(d) the ions carrying more opposite charge to that of sol particle are effective in coagulation
Given below are a few electrolytes, indicate which one among them will bring about the coagulation of a gold sol quickest and in the least of concentration?(a) $\mathrm{NaCl}$(b) $\mathrm{MgSO}_{4}$(C) $\mathrm{Nl}_{2}\left(\mathrm{SO}_{4}\right)_{3}$(d) $\mathrm{K}_{4}\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]$
The ability of an ion to bring about coagulation of a given colloid depends upon:(a) its size(b) the magnitude of its charge only(c) the sign of its charge alone(d) both magnitude and sign of its charge
An emulsifying agent is a substance which?(a) Stabilizes the emulsion(b) De-stabilizes the emulsion(c) Coagulates the emulsion(d) Break the interfacial film between suspended particle and medium
Colloidal solution of gold is prepared by:(a) colloidal mill(b) double decomposition method(c) Bredig's method(d) peptization
The formation of colloid from suspension is:(a) peptisation(b) condensation(c) sedimentation(d) fragmentation
The method usually employed for the destruction of a colloidal solution is:(a) dialysis(b) addition of electrolytes(c) diffusion through animal membrane(d) condensation
Which of the following has minimum flocculation value for positively charged sol?(A) $\mathrm{Cl}^{-}$(b) $\mathrm{SO}_{4}^{2-}$(C) $\mathrm{PO}_{4}^{3-}$(d) $\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]^{4-}$
Which of the following will have the highest coagulating power for $\mathrm{Fe}(\mathrm{OH})_{3}$ conon(a) $\mathrm{PO}_{4}^{3-}$(b) $\mathrm{SO}_{4}^{2-}$(c) $\mathrm{Ca}^{2+}$(d) $\mathrm{Al}^{3+}$
Artifical rain is caused by spraying:(a) Opposite charged collidal dust over a cloud(b) Same charged collidal dust over a cloud(c) Both(d) None of these
Colloids can be purified by:(a) condensation(b) peptization(c) coagulation(d)' dialysis
Dialysis can seperate, which of the following in addition to the glucose from the human blood?(a) Sucrose(b) Fructose(c) Alcohol(d) Proteins
Protective sols are:(a) lyophilic(b) lyophobic(c) both (a) and (b)(d) none of these
Electro-osmosis is observed when:(a) dispersion medium particles begins to move in an electric field(b) dispersed phase begins to move in an electric field(c) both (a) and (b)(d) none of the above
On adding $\mathrm{AgNO}_{3}$ solution into KI solution, a negatively charged colloidal sol is obtained when they are in:(a) $50 \mathrm{~mL}$ of $0.1 \mathrm{M} \mathrm{AgNO}_{3}+50 \mathrm{~mL}$ of $0.1 M \mathrm{KI}$(b) $50 \mathrm{~mL}$ of $0.1 \mathrm{M} \mathrm{AgNO}_{3}+50 \mathrm{~mL}$ of $0.2 \mathrm{M} \mathrm{KI}$(c) $50 \mathrm{~mL}$ of $0.2 \mathrm{M} \mathrm{AgNO}_{3}+50 \mathrm{~mL}$ of $0.1 \mathrm{M} \mathrm{KI}$(d) None of these
A sol is prepared by addition of excess of $\mathrm{AgNO}_{3}$ solution in KI solution. The charge likely to develop on colloidal particles is:(a) positive(b) negative(c) no charge(d) both charges
The gold numbers of protective colloids $A, B, C$ and $D$ are $0.04,0.004,10$ and 40 respectively. The protective powers of $A, B, C$ and $D$ are in the order:(A) $A>B>C>D$(b) $B>A>C>D$(C) $D>C>A>B$(d) $D>C>B>A$
In Brownian motion, the paths of the particles are:(a) linear(b) curved(c) zig-zag(d) uncertain
Which one of the following is not represented by sols?(a) Adsorption(b) Tyndall effect(c) Flocculation(d) Paramagnetism
The Tyndall effect associated with colloidal particles is due to:(a) presence of electrical charges(b) scattering of light(c) absorption of light(d) reflection of light
Blue colour of the sky is due to:(a) absorption of light by dust particles(b) reflection of light by dust particles(c) scattering of light by dust particles(d) presence of clouds
The apparatus used to coagulate carbon particles from smoke is called:(a) cottrel smoker(b) cottrell precipitator(c) cottrell absorber(d) none of these