# 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

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

## Questions 3 of 50

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

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

Physical adsorption is due to Vander Wall's forces

Chemical adsorption decreases at high temperature and low pressure

## Questions 5 of 50

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

Absorbate

Absorber

## Questions 6 of 50

Question:Adsorption is phenomenon is which a substance

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 ?

Homogeneous catalysis

Acid base catalysis

Heterogeneous catalysis

Enzyme catalysis

## Questions 8 of 50

Question:Adsorption due to strong chemical forces is called

Chemisorption

Physiosorption

Both 1 and 2

## Questions 9 of 50

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

$$A{g^ + }$$ 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

$$Mn{O_2}$$ 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

Autocatalyst

Poison

Promotor

Positive catalyst

## Questions 12 of 50

Question:Reactions in Zeolite catalysts depend on

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

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

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 $$C{H_3}Cl$$

$$Ni$$

Anhydrous $$AlC{l_3}$$

$$Pd$$

$$Pt$$

## Questions 16 of 50

Question:A catalyst in a chemical reaction

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

Heterogeneous catalyst

Autocatalyst

Homogenous catalyst

Induced catalyst

## Questions 18 of 50

Question:Catalyst used in hydrogenation of oils is

$$Pt$$

$$Mo$$

$$Fe$$

$$Ni$$

## Questions 19 of 50

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

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

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

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

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

## 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

A positive catalyst

A negative catalyst

An autocatalyst

A poison

## Questions 21 of 50

Question:Which of the following statements is wrong

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

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

Nickel

Platinum

Cobalt

All of these

## Questions 24 of 50

Question:Which of the following is true about catalyst

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

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

0.025

0.25

0.5

250

## Questions 27 of 50

Question:Light scattering in colloidal particles is

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

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

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

Smoke

Clouds

Emulsion

Jellies

## Questions 31 of 50

Question:A liquid aerosol is a colloidal system of

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

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

Nature of colloidal substance

Temperature of the solution

Both of these

None of these

## Questions 34 of 50

Question:An emulsifier

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

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

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

Peptisation

Electrophoresis

None of these

## Questions 38 of 50

Question:In dialysis, colloidal particles are separated from

Solvent

Dispersed phase

Ions of electrolytes

Particles of dispersion medium

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

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

Foam

Gel

Gas

Air

## Questions 42 of 50

Question:Size of colloidal particle is

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

$$A{s_2}{S_3}$$

$$A{s_2}{O_3}$$

$$A{s_2}S$$

$$A{s_2}{H_2}$$

## Questions 44 of 50

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

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

$$Fe{(OH)_3}$$

Gelatin

$$A{s_2}{S_3}$$

None of these

## Questions 46 of 50

Question:At isoelectric point

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

Pt

Fe

Ag

Au

## Questions 48 of 50

Question:Gold number is maximum for the lyophilic sol is

Gelatin

Haemoglobin

Sodium oleate

Potato starch

## Questions 49 of 50

Question:Muddy water can be purified through coagulation using

Common salt

Alums

Sand

Lime

## Questions 50 of 50

Question:Fog is a colloidal solution of