Surface Chemistry Test 2

Total Questions:50 Total Time: 75 Min

Remaining:

 

Questions 1 of 50

Question:A solid acts as an adsorbent because it has

Answers Choices:

A definite shape

Small pores in it

Unsaturated valencies

A high lattice energy

Questions 2 of 50

Question:Point out the wrong statement : Physical adsorption is characterised by

Answers Choices:

Attraction due to weak Vander Waal's forces

Irreversible nature of adsorption

Multimolecular adsorption layers

Decrease in adsorption with increase in temperature

Questions 3 of 50

Question:Physical adsorption is essentially quite appreciable

Answers Choices:

At room temperature

At higher temperature

At lower temperature

None of these

Questions 4 of 50

Question:Adsorption increase when

Answers Choices:

Temperature increases

Temperature decreases

Temperature remains constant

None of these

Questions 5 of 50

Question:Physical adsorption is inversely proportional to the

Answers Choices:

Volume

Concentration

Temperature

All of these

Questions 6 of 50

Question:50 ml of 1 M oxalic acid is shaken with 0.5 gm of wood charcoal. The final concentration of the solution after adsorption is 0.5 M. Amount of oxalic acid absorbed per gm of charcoal is

Answers Choices:

3.45 gm

3.15 gm

6.30 gm

None

Questions 7 of 50

Question:What is the role of a catalyst in a catalysed reaction

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Lowers the activation energy

Increases the activation energy

Affects the free energy change

Affects the enthalpy change

Questions 8 of 50

Question:The catalyst used in the lead chamber process of sulphuric acid manufacture is

Answers Choices:

Platinum

Oxide of nitrogen

Nickel

Vanadium compounds

Questions 9 of 50

Question:Hydrolysis of ethyl acetate is catalysed by aqueous

Answers Choices:

\(N{a_2}S{O_4}\)

\({K_2}S{O_4}\)

\({H_2}S{O_4}\)

\(BaS{O_4}\)

Questions 10 of 50

Question:Which of the following statements about a catalyst is true

Answers Choices:

It lowers the energy of activation

The catalyst altered during the reaction is regenerated

It does not alter the equilibrium

All of these

Questions 11 of 50

Question:Addition of catalyst in a system

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Increases equilibrium concentrations

No effect on equilibrium concentrations

Decreases equilibrium concentrations

Increases rate of forward reaction and decreases rate of backward reaction

Questions 12 of 50

Question:In which of the following processes, platinum is used as a catalyst

Answers Choices:

Oxidation of ammonia to form nitric acid

Hardening of oils

Production of synthetic rubber

Synthesis of methanol

Questions 13 of 50

Question:Which one is false in the following statement

Answers Choices:

A catalyst is specific in its action

A very small amount of the catalyst alters the rate of a reaction

The number of free valencies on the surface of the catalyst increases on subdivision

\(Ni\) is used as catalyst in the manufacture of ammonia

Questions 14 of 50

Question:In the redox reaction\(2MnO_4^ - + 5{C_2}O_4^{2 - } + 16{H^ + }\) \( \leftrightarrow \)\(2M{n^{2 + }} + 10C{O_2} + 8{H_2}O\) The ion acting as autocatalyst is

Answers Choices:

\(MnO_4^ - \)

\({C_2}O_4^{2 - }\)

\({H^ + }\)

\(M{n^{2 + }}\)

Questions 15 of 50

Question:Which of the following types of metals form the most efficient catalysts

Answers Choices:

Alkali metals

Alkaline earth metals

Transition metals

All of these

Questions 16 of 50

Question:Formation of ammonia from \({H_2}\) and \({N_2}\) by Haber's process using \(Fe\) is an example of

Answers Choices:

Heterogeneous catalysis

Homogeneous catalysis

Enzyme catalysis

Non-catalytic process

Questions 17 of 50

Question:Tyndall effect would be observed in a

Answers Choices:

Solution

Colloidal solution

Precipitate

Solvent

Questions 18 of 50

Question:Ferric hydroxide sol is positively charged colloid. The coagulating power of \(NO_3^ - ,\,SO_4^{2 - }\) and \(PO_4^{3 - }\) ions would be in the order

Answers Choices:

\(NO_3^ - > SO_4^{2 - } > PO_4^{3 - }\)

\(SO_4^{2 - } > NO_3^ - > PO_4^{3 - }\)

\(PO_4^{3 - } > SO_4^{2 - } > NO_3^ - \)

\(NO_3^ - = SO_4^{2 - } = PO_4^{3 - }\)

Questions 19 of 50

Question:A colloidal solution can be purified by

Answers Choices:

Filtration

Peptization

Coagulation

Dialysis

Questions 20 of 50

Question:Which of the following is an emulsifier

Answers Choices:

Soap

Water

Oil

\(NaCl\)

Questions 21 of 50

Question:Suspensions are

Answers Choices:

Visible to naked eye

Invisible through microscope

Not visible by any means

Invisible under electron microscope

Questions 22 of 50

Question:Gelatin is mostly used in making ice cream in order to

Answers Choices:

Prevent making of colloid

To stabilise the colloid and prevent crystallization

To stabilise mixture

To enrich the aroma

Questions 23 of 50

Question:Tyndall phenomenon is exhibited by

Answers Choices:

\(NaCl\) solution

Starch solution

Urea solution

\(FeC{l_3}\) solution

Questions 24 of 50

Question:The colloidal solution of gelatin is known

Answers Choices:

Solvent loving sol

Reversible sol

Hydrophilic colloids

All of these

Questions 25 of 50

Question:The zig-zag motion of colloidal particles is due to

Answers Choices:

Small size of colloidal particles

Large size of colloidal particles

The conversion of potential energy into kinetic energy

Bombardment on colloidal particles by molecules of dispersion medium

Questions 26 of 50

Question:Butter is a colloid. It is formed when

Answers Choices:

Fat is dispersed in solid casein

Fat globules are dispersed in water

Water is dispersed in fat

Casein is suspended in \({H_2}O\)

Questions 27 of 50

Question:Colloidal solution cannot be obtained from two such substances which are

Answers Choices:

Insoluble in each other

In same physical state

In different physical state

None of these

Questions 28 of 50

Question:Which of the following reactions leads to the formation of a substance in the colloidal state (in presence of excess of \(HCl\))

Answers Choices:

\(Cu + HgC{l_2} \to CuC{l_2} + Hg\)

\(2HN{O_3} + 3{H_2}S \to 3S + 4{H_2}O + 2NO\)

\(2Mg + C{O_2} \to 2MgO + C\)

\(Cu + CuC{l_2} \to C{u_2}C{l_2}\)

Questions 29 of 50

Question:The difference between a lyophilic and lyophobic colloid is in their

Answers Choices:

Particle size

Behaviour towards dispersion medium

Filtrability

None of these

Questions 30 of 50

Question:When a substance comes in colloidal state the surface area of the particles

Answers Choices:

Increases

Decreases

Remains unchanged

First increases then decreases

Questions 31 of 50

Question:Which of the impurity can be separated from a solution by electrodialysis

Answers Choices:

Alcohol

Alum

Sugar

Parchment paper

Questions 32 of 50

Question:Sulphur sol contains

Answers Choices:

Discrete sulphur atoms

Discrete sulphur molecules

Large agreegates of sulphur molecules

Water dispersed in solid sulphur

Questions 33 of 50

Question:Pick out the statement which is not relevant in the discussion of colloids

Answers Choices:

Sodium aluminium silicate is used in the softening of hard water

Potash alum is used in shaving rounds and as antiseptic in medicine

Artificial rain is caused by throwing electrified sand on the clouds from an aeroplane

Deltas are formed at a place where the river pours its water into the sea

Questions 34 of 50

Question:Surface tension of lyophilic sols is

Answers Choices:

Lower than \({H_2}O\)

More than \({H_2}O\)

Equal to \({H_2}O\)

None of these

Questions 35 of 50

Question:Colour of colloidal solution is due to

Answers Choices:

Different size of colloidal particles

Due to formation of complex

Due to formation of hydrated crystal

None of these

Questions 36 of 50

Question:Which of the following is property of colloid

Answers Choices:

Scattering of light

They show attraction

Dialysis

Emulsion

Questions 37 of 50

Question:The size of particles in suspension, true solution and colloidal solution varies in the order

Answers Choices:

Suspension > Colloidal > True solution

Suspension > (Colloidal + True solution)

True solution > Suspension > Colloidal

None of these

Questions 38 of 50

Question:Liquid-liquid sols are known as

Answers Choices:

Aerosols

Emulsions

Foam

Gel

Questions 39 of 50

Question:Tyndall effect depends upon the

Answers Choices:

Charge on the colloidal particles

Osmotic pressure of colloidal solution

Difference between the refractive indices of dispersed phase and dispersion medium

Size of colloidal particles

Questions 40 of 50

Question:Which one of the sols acts as protective colloid

Answers Choices:

\(A{s_2}{S_3}\)

Gelatin

\(Au\)

\(Fe{(OH)_3}\)

Questions 41 of 50

Question:Which one is Freundlich's equation

Answers Choices:

\(\frac{x}{m} = \log \,K + \frac{1}{n}\log \,P\)

\(\frac{x}{m} = \exp \,( - KP)\)

\(\frac{x}{m} = K{P^2}\)

\(\log \frac{x}{m} = \log K + \frac{1}{n}\log \,C\)

Questions 42 of 50

Question:Ferric chloride is applied to stop bleeding cut because

Answers Choices:

\(F{e^{3 + }}\) ion coagulates blood, which is a negatively charged sol

\(F{e^{3 + }}\) ion coagulates blood, which is a positively charged sol

\(C{l^ - }\) coagulates blood, which is a positively charged sol

\(C{l^ - }\) ion coagulates blood, which is a negatively charged sol

Questions 43 of 50

Question:Fog is an example of colloidal system

Answers Choices:

Liquid dispersed in gas

Gas dispersed in gas

Solid dispersed in gas

Gas dispersed in liquid

Questions 44 of 50

Question:In the measurement of gold number, the useful electrolyte is

Answers Choices:

\(AuC{l_3}\)

\(NaCl\)

\(AlC{l_3}\)

\(FeC{l_3}\)

Questions 45 of 50

Question:Which one is an example of multimolecular colloid system

Answers Choices:

Soap dispersed in water

Protein dispersed in water

Gold dispersed in water

Gum dispersed in water

Questions 46 of 50

Question:Metals like Pt and Pd can adsorb large volume of hydrogen under specific conditions. Such adsorbed hydrogen by the metal is known as

Answers Choices:

Occluded hydrogen

Absorbed hydrogen

Reactive hydrogen

Atomic hydrogen

Questions 47 of 50

Question:Which of the following is the best protective colloid

Answers Choices:

Gelatin (Gold No. = 0.005)

Gum arabic (Gold No. = 0.15)

Egg albumin (Gold No. = 0.08)

None of these

Questions 48 of 50

Question:The gold number of A, B C and D are 0.04, 0.002, 10 and 25 respectively. Protective power of A, B, C and D are in order

Answers Choices:

\(A > B > C > D\)

\(B > A > C > D\)

\(D > C > B > A\)

\(C > A > B > D\)

Questions 49 of 50

Question:Lyophilic sols are more stable than lyophobic sols because their particles are

Answers Choices:

Positively charged

Negatively charged

All soluble

Attract each other

Are heavier

Questions 50 of 50

Question:Oils and fats are obtained by saponification of potassium stearate. Its formula is \(C{H_3} - {(C{H_2})_{16}} - CO{O^ - }{K^ + }\). Lyophobic end of atom is \((C{H_3})\) and lyophilic end is \(CO{O^ - }{K^ + }\). potassium stearate is example of

Answers Choices:

Lyophobic colloids

Lyophilic colloids

Poly molecular colloids

Macromolecular colloids

Combined colloids or Miscells