Surface Chemistry Test 1

Total Questions:50 Total Time: 75 Min

Remaining:

 

Questions 1 of 50

Question:Wood charcoal is used to decolourise sugar because it

Answers Choices:

Adsorbs coloured material

Absorbs decolorised material

Reduces coloured material

None of these

Questions 2 of 50

Question:If the absorbate is held on a surface by weak Vander Waal's forces, the absorption process is called

Answers Choices:

Physical adsorption

Chemical adsorption

Heat of adsorption

Enthalpy of adsorption

Questions 3 of 50

Question:When the temperature is raised, the viscosity of liquid decreases, this is because

Answers Choices:

Decreased volume of the solution

Increase in temperature increases the average kinetic energy of molecules, which overcome the attractive force between them

Decreased covalent and hydrogen bond forces

Increased attraction between molecules

Questions 4 of 50

Question:Which of the following statement is not correct

Answers Choices:

Physical adsorption is due to Vander Wall's forces

Chemical adsorption decreases at high temperature and low pressure

Physical adsorption is reversible

Adsorption energy for a chemical adsorption is generally greater than that of physical adsorption

Questions 5 of 50

Question:In adsorption of oxalic acid on activated charcoal, the activated charcoal is known as

Answers Choices:

Adsorbent

Absorbate

Adsorber

Absorber

Questions 6 of 50

Question:Adsorption is phenomenon is which a substance

Answers Choices:

Goes into the body of the other substance

Remains close the other substance

Accumulates on the surface of the other substance

None of these

Questions 7 of 50

Question:Which of the following kinds of catalysis can be explained by the adsorption theory ?

Answers Choices:

Homogeneous catalysis

Acid base catalysis

Heterogeneous catalysis

Enzyme catalysis

Questions 8 of 50

Question:Adsorption due to strong chemical forces is called

Answers Choices:

Chemisorption

Physiosorption

Reversible adsorption

Both 1 and 2

Questions 9 of 50

Question:In neutralisation of KI by \(AgN{O_3}\) positive charge is due to absorption of

Answers Choices:

\(A{g^ + }\) ions

Ag

I ions

Both 1 and 2

Questions 10 of 50

Question:When \(KCl{O_3}\) is heated, it decomposes into \(KCl + {O_2}\). If some \(Mn{O_2}\) is added, the reaction goes much faster because

Answers Choices:

\(Mn{O_2}\) decomposes to give \({O_2}\)

\(Mn{O_2}\) provides heat by reacting

Better contact is provided by \(Mn{O_2}\)

\(Mn{O_2}\) acts as a catalyst

Questions 11 of 50

Question:In the reaction \(2S{O_2} + {O_2} \to 2S{O_3}\), \(A{s_2}{O_3}\) acts as a

Answers Choices:

Autocatalyst

Poison

Promotor

Positive catalyst

Questions 12 of 50

Question:Reactions in Zeolite catalysts depend on

Answers Choices:

Pores

Apertures

Size of cavities

All of these

Questions 13 of 50

Question:Which one of the following statement is wrong in case of enzyme catalysis

Answers Choices:

Enzymes work best at an optimum temperature

Enzymes work at an optimum \(pH\)

Enzymes are highly specific for substances

An enzyme raises activation energy

Questions 14 of 50

Question:Which of the following catalyses the conversion of glucose into ethanol

Answers Choices:

Zymase

Invertase

Maltase

Diastase

Questions 15 of 50

Question:Which of the following is used as a catalyst in the manufacture of toluene from benzene with \(C{H_3}Cl\)

Answers Choices:

\(Ni\)

Anhydrous \(AlC{l_3}\)

\(Pd\)

\(Pt\)

Questions 16 of 50

Question:A catalyst in a chemical reaction

Answers Choices:

Does not initiate a reaction

Increases the activation energy of the reaction

Changes the equilibrium constant of a reaction

Does not change the rate of the reaction

Questions 17 of 50

Question:Platinized asbestos is used as a catalyst in the manufacture of \({H_2}S{O_4}\). It is an example of

Answers Choices:

Heterogeneous catalyst

Autocatalyst

Homogenous catalyst

Induced catalyst

Questions 18 of 50

Question:Catalyst used in hydrogenation of oils is

Answers Choices:

\(Pt\)

\(Mo\)

\(Fe\)

\(Ni\)

Questions 19 of 50

Question:Amongst the following chemical reactions, the one representing homogeneous catalysis is

Answers Choices:

\({N_2}(g) + 3{H_2}(g) \to 2N{H_3}(g)\)

\(2S{O_2}(g) + {O_2}(g) \to 2S{O_3}(g) + 2NO(g)\)

\(CO(g) + 3{H_2}(g) \to C{H_4}(g) + {H_2}O\)

\(2S{O_2}(g) + {O_2}(g) \to 2S{O_3}(g)\)

Questions 20 of 50

Question:Platinised asbestos helps in the formation of \(S{O_3}\) form \(S{O_2}\) and \({O_2}\). But, if even a small amount of \(A{s_2}{O_3}\) is present the platinised asbestos does not help in the formation of \(S{O_3}\). \(A{s_2}{O_3}\) acts here as

Answers Choices:

A positive catalyst

A negative catalyst

An autocatalyst

A poison

Questions 21 of 50

Question:Which of the following statements is wrong

Answers Choices:

Catalysts can aid a rapid reaching of the equilibrium position, but do not change the position of the equilibrium

Homogeneous catalysis generally involves an equilibrium reaction between at least one of the reactants and the catalyst

Heterogeneous catalysis involves chemisorption on the surface of the catalyst

Positive catalysts raise the energy of activation of the reaction they catalyse

Questions 22 of 50

Question:A catalyst is used to

Answers Choices:

Increase the product

Increase or decrease the rate of reaction

Increase or decrease the products

Decrease the products

Questions 23 of 50

Question:The transition metal used as a catalyst is

Answers Choices:

Nickel

Platinum

Cobalt

All of these

Questions 24 of 50

Question:Which of the following is true about catalyst

Answers Choices:

It initiates reaction

It changes equilibrium point

It increase average kinetic energy

It accelerates the rate of reaction

Questions 25 of 50

Question:Zig-zag motion (eratic motion) of particles in colloid was observed by

Answers Choices:

Tyndall

Zsigmondy

Robert brown

Thomas Graham

Questions 26 of 50

Question:On addition of one ml solution of \(10\% NaCl\) to 10 ml gold sol in the presence of 0.25 gm of starch, the coagulation is just prevented. Starch has the following gold number

Answers Choices:

0.025

0.25

0.5

250

Questions 27 of 50

Question:Light scattering in colloidal particles is

Answers Choices:

Visible to naked eye

Not visible by any means

Visible under ordinary microscope

Visible under ultra-microscope

Questions 28 of 50

Question:Flocculation value is expressed in terms of

Answers Choices:

millimole per litre

mole per litre

gram per litre

mole per millilitre

Questions 29 of 50

Question:Which of the following terms is not related with colloids

Answers Choices:

Dialysis

Ultrafiltration

Wavelength

Brownian movement

Questions 30 of 50

Question:When dispersed phase is liquid and dispersion medium is gas, then the colloidal system is called

Answers Choices:

Smoke

Clouds

Emulsion

Jellies

Questions 31 of 50

Question:A liquid aerosol is a colloidal system of

Answers Choices:

A liquid dispersed in a solid

A liquid dispersed in a gas

A gas dispersed in a liquid

A solid dispersed in a gas

Questions 32 of 50

Question:The blue colour of water in the sea is due to

Answers Choices:

Refraction of blue light by the impurities in sea water

Reflection of blue sky by sea water

Scattering of blue light by water molecules

Absorption of other colours except the blue colour by water molecules

Questions 33 of 50

Question:The rate of dialysis depends upon

Answers Choices:

Nature of colloidal substance

Temperature of the solution

Both of these

None of these

Questions 34 of 50

Question:An emulsifier

Answers Choices:

Accelerates the dispersion

Homogenises the emulsion

Stabilizes the emulsion

Aids the flocculation of emulsion

Questions 35 of 50

Question:Which characteristic is true in respect of colloidal particle

Answers Choices:

They always have two phases

They are only in liquid state

They can't be electrolysed

They are only hydrophilic

Questions 36 of 50

Question:Gold number is a measure of the

Answers Choices:

Protective action by a lyophilic colloid on a lyophobic colloid

Protective action by a lyophobic colloid on a lyophilic colloid

Number of \(mg\) of gold in a standard red gold sol

Stability of gold sol

Questions 37 of 50

Question:A cleared solution which is again converted into colloidal solution, the process is called

Answers Choices:

Peptisation

Electrolytic addition

Electrophoresis

None of these

Questions 38 of 50

Question:In dialysis, colloidal particles are separated from

Answers Choices:

Solvent

Dispersed phase

Ions of electrolytes

Particles of dispersion medium

Questions 39 of 50

Question:When sugar is added to a colloidal solution it brings about

Answers Choices:

Ionization

Coagulation

Peptization

None of these

Questions 40 of 50

Question:Colloidal solutions of metals like gold, silver and platinum are generally prepared by using

Answers Choices:

Peptization

Bredig's arc method

Exchange of solvent

Oxidation method

Questions 41 of 50

Question:High concentration of gelatin in water on heating gives colloidal solution, which is called

Answers Choices:

Foam

Gel

Gas

Air

Questions 42 of 50

Question:Size of colloidal particle is

Answers Choices:

1 to 10\(\mathop A\limits^{\,\,\,\,\,\,0} \)

20 to 50\(\mathop A\limits^{\,\,\,\,\,\,0} \)

10 to 1000\(\mathop A\limits^{\,\,\,\,\,\,0} \)

1 to 280\(\mathop A\limits^{\,\,\,\,\,\,0} \)

Questions 43 of 50

Question:Which of the following colloids are formed when hydrogen sulphide gas is passed through a cold solution of arsenious oxide

Answers Choices:

\(A{s_2}{S_3}\)

\(A{s_2}{O_3}\)

\(A{s_2}S\)

\(A{s_2}{H_2}\)

Questions 44 of 50

Question:The simplest way to check whether a system is colloidal, is

Answers Choices:

Tyndall effect

Electro dialysis

Brownian movement

Finding out particle size

Questions 45 of 50

Question:Which of the following can stabilize gold sol from coagulation by \(NaCl\) solution

Answers Choices:

\(Fe{(OH)_3}\)

Gelatin

\(A{s_2}{S_3}\)

None of these

Questions 46 of 50

Question:At isoelectric point

Answers Choices:

Colloidal sol becomes highly stable

Precipitation of a colloidal sol takes place

Colloidal particles becomes uncharged

Peptization can be carried out

Questions 47 of 50

Question:Bredig arc method can not be used to prepare colloidal solution of which of the following

Answers Choices:

Pt

Fe

Ag

Au

Questions 48 of 50

Question:Gold number is maximum for the lyophilic sol is

Answers Choices:

Gelatin

Haemoglobin

Sodium oleate

Potato starch

Questions 49 of 50

Question:Muddy water can be purified through coagulation using

Answers Choices:

Common salt

Alums

Sand

Lime

Questions 50 of 50

Question:Fog is a colloidal solution of

Answers Choices:

Solid in gas

Liquid in gas

Gas in liquid

Gas in solid