Surface Chemistry Test 5

Total Questions:50 Total Time: 75 Min

Remaining:

 

Questions 1 of 50

Question:In the adsorption of acetic acid on activated charcoal, the acetic acid is an

Answers Choices:

Adsorber

Absorber

Adsorbent

Adsorbate

Questions 2 of 50

Question:Sticking of one substance at the surface of another is called

Answers Choices:

Absorption

Chemisorption

Adsorption

Desorption

Questions 3 of 50

Question:The charge on colloidal particles is due to

Answers Choices:

Presence of electrolyte

Very small size of particles

Adsorption of ions from the solution

None of these

Questions 4 of 50

Question:Which one of the following substances adsorb hydrogen gas most strongly

Answers Choices:

Activated carbon

Silica gel

Platinum black

Iron powder

Questions 5 of 50

Question:According to the adsorption theory of catalysis, the speed of the reaction increases because

Answers Choices:

Adsorption lowers the activation energy of the reaction

The concentration of reactant molecules at the active centres of the catalyst becomes high due to adsorption

In the process of adsorption, the activation energy of the molecules becomes large

Adsorption produces heat which increases the speed of the reaction

Questions 6 of 50

Question:In Freundlich adsorption, isotherm adsorption is proportional to pressure P as

Answers Choices:

\({P^0}\)

\(P\)

\({P^n}\)

\({P^{1/n}}\)

Questions 7 of 50

Question:The extent of adsorption of a gas on a solid depends on

Answers Choices:

Nature of the gas

Pressure of the gas

Temperature of the gas

All are correct

Questions 8 of 50

Question:Activated charcoal is used to remove colouring matter from pure substances. It works by

Answers Choices:

Oxidation

Reduction

Bleaching

Adsorption

Questions 9 of 50

Question:Mark the correct statement in a reversible reaction

Answers Choices:

The catalyst catalyses the forward reaction

The catalyst catalyses the backward reaction

The catalyst influences the direct and the reverse reaction to the same extent

The catalyst increases the rate of forward reaction and decreases the rate of backward reaction

Questions 10 of 50

Question:The role of a catalyst in a reversible reaction is to

Answers Choices:

Increase the rate of forward reaction

Decrease the rate of backward reaction

Alter the equilibrium constant of the reaction

Allow the equilibrium to be achieved quickly

Questions 11 of 50

Question:The catalyst used in the contact process for manufacturing of sulphuric acid is

Answers Choices:

Copper

Iron/aluminium oxide

Vanadium pentoxide

Platinized asbestos

Questions 12 of 50

Question:For the functioning of enzymes which of the following statements is not correct

Answers Choices:

An optimum temperature is needed

An optimum pH is needed

They are substrate specific

They always increase activation energy

Questions 13 of 50

Question:In the reversible reaction a catalyst is the substance which

Answers Choices:

Increases the rate of the forward reaction

Decreases the value of enthalpy change in the reaction

Reduces the time required for reaching the equilibrium state in the reaction

Decreases the rate of the reverse reaction

Questions 14 of 50

Question:In the titration between oxalic acid and acidified potassium permanganate, the manganous salt formed catalyses the reaction. The manganous salt is

Answers Choices:

A promoter

A positive catalyst

An autocatalyst

None of these

Questions 15 of 50

Question:Which one of the following statements is incorrect in the case of heterogeneous catalysis

Answers Choices:

The catalyst lowers the energy of activation

The catalyst actually forms a compound with the reactant

The surface of the catalyst plays a very important role

There is no change in the energy of activation

Questions 16 of 50

Question:In the Ostwald's process for the manufacture of \(HN{O_3}\), the catalyst used is

Answers Choices:

\(Mo\)

\(Fe\)

\(Ni\)

\(Pt\)

Questions 17 of 50

Question:A biological catalyst is essentially

Answers Choices:

An amino acid

A carbohydrate

The nitrogen molecule

An enzyme

Questions 18 of 50

Question:A catalyst added to a reaction mixture

Answers Choices:

Increases the equilibrium constant

Decreases the equilibrium constant

Does not change the equilibrium constant

None of these

Questions 19 of 50

Question:The process which is catalysed by one of the products is called

Answers Choices:

Acid-base catalysis

Autocatalysis

Negative catalysis

None of these

Questions 20 of 50

Question:Adam's catalyst is

Answers Choices:

Platinum

Iron

Molybdenum

Nickel

Questions 21 of 50

Question:Which of the following is most effective in coagulating a ferric hydroxide sol

Answers Choices:

\(KCl\)

\(KN{O_3}\)

\({K_2}S{O_4}\)

\({K_3}[Fe{(CN)_6}]\)

Questions 22 of 50

Question:Sky looks blue due to

Answers Choices:

Dispersion effect

Reflection

Transmission

Scattering

Questions 23 of 50

Question:The stability of lyophilic colloids is due to

Answers Choices:

Charge on their particles

A layer of dispersion medium on their particles

The smaller size of their particles

The large size of their particles

Questions 24 of 50

Question:Milk is a colloid in which

Answers Choices:

A liquid is dispersed in liquid

A solid is dispersed in liquid

A gas is dispersed in liquid

Some suger is dispersed in water

Questions 25 of 50

Question:Detergent action of soap is due to

Answers Choices:

Emulsification properties

Hydrolysis

Ionization

High molecular weight

Questions 26 of 50

Question:When dispersion medium is water, the colloidal system is called

Answers Choices:

Sol

Aerosol

Organosol

Aquasol

Questions 27 of 50

Question:When a colloidal solution is observed under a microscope we can see

Answers Choices:

Light scattered by colloidal particles

Size of colloidal particles

Shape of colloidal particles

Relative size of the colloidal particles

Questions 28 of 50

Question:Property of the colloidal solution is due to

Answers Choices:

Nature of dispersed phase

Nature of dispersion medium

Physical state of dispersed phase

Temperature of the system

Questions 29 of 50

Question:Bleeding is stopped by the application of ferric chloride. This is because

Answers Choices:

Ferric chloride seal the blood cells.

Blood starts flowing in the other direction

Blood is coagulated and blood vessel is sealed

None of these

Questions 30 of 50

Question:The colloidal particles can pass through

Answers Choices:

Filter paper as well as animal membrane

Animal membrane but not through filter paper

Filter paper but not through animal membrane

Semipermeable membrane

Questions 31 of 50

Question:Silver iodide is used for producing artificial rain because \(AgI\)

Answers Choices:

Is easy to spray at high altitudes

Is easy to synthesize

Has crystal structure similar to ice

Is insoluble in water

Questions 32 of 50

Question:Surface water contains

Answers Choices:

Salt

Salt and organic compound

Organic compounds

Suspended impurities

Questions 33 of 50

Question:Which one of the following properties of colloids is related with scattering of light

Answers Choices:

Diffusion

Peptization

Tyndall effect

Brownian movement

Questions 34 of 50

Question:Which one of the following is a hydrophilic colloidal sol

Answers Choices:

Barium hydroxide sol

Arsenic sulphide sol

Starch solution

Silver chloride sol

Questions 35 of 50

Question:The minimum quantity of sodium chloride which is necessary to precipitate 10 litres of sol in two hours is 0.585 gm. The flocculation value of sodium chloride is

Answers Choices:

0.585

0.0585

0.1

One

Questions 36 of 50

Question:Which one is an example of miceller system

Answers Choices:

Soap + water

Protein + water

Rubber + benzene

\(A{s_2}{O_3} + Fe{(OH)_3}\)

Questions 37 of 50

Question:Minimum concentration of electrolyte which can precipitate any sol is

Answers Choices:

Peptization value

Gold number

Avogadro's number

Flocculation value

Questions 38 of 50

Question:Milk is

Answers Choices:

Dispersed fats in oil

Dispersed fats in water

Dispersed water in fats

Dispersed water in oil

Questions 39 of 50

Question:Gold number is related with

Answers Choices:

Colloids

Radioactivity

Gas equation

Kinetic energy

Questions 40 of 50

Question:Small liquid droplets dispersed in another liquid is called

Answers Choices:

Gel

Emulsion

Suspension

True solution

Questions 41 of 50

Question:Which of the following is used for the destruction of colloids

Answers Choices:

Dialysis

Condensation

By ultrafiltration

By adding electrolyte

Questions 42 of 50

Question:Which is a colloid

Answers Choices:

Sugar solution

Urea solution

Silicic acid

\(NaCl\) solution

Questions 43 of 50

Question:Alum helps in purifying water by

Answers Choices:

Forming Si complex with clay particles

Sulphate part which combines with the dirt and removes it

Aluminium which coagulates the mud particles

Making mud water soluble

Questions 44 of 50

Question:Maximum coagulation power is in

Answers Choices:

\(N{a^ + }\)

\(B{a^{ + + }}\)

\(A{l^{ + + + }}\)

\(S{n^{ + + + + }}\)

Questions 45 of 50

Question:Which of the following substances is not used for preparing lyophilic sols

Answers Choices:

Starch

Gum

Gelatin

Metal sulphide

Questions 46 of 50

Question:Hydrophilic sols are

Answers Choices:

Reversible

Irreversible

Unstable

None of these

Questions 47 of 50

Question:Soap essentially forms a colloidal solution in water and removes the greasy matter by

Answers Choices:

Absorption

Emulsification

Coagulation

None of these

Questions 48 of 50

Question:Lyophilic sols are

Answers Choices:

Irreversible sols

They are prepared from inorganic compound

Coagulated by adding electrolytes

Self-stabilizing

Questions 49 of 50

Question:The volume of a colloidal particle, \({V_C}\) as compared to the volume of a solute particle in a true solution \({V_S},\) could be

Answers Choices:

\(\frac{{{V_C}}}{{{V_S}}}\tilde --1\)

\(\frac{{{V_C}}}{{{V_S}}}\tilde --{10^{23}}\)

\(\frac{{{V_C}}}{{{V_S}}}\tilde --{10^{ - 3}}\)

\(\frac{{{V_C}}}{{{V_S}}}\tilde --{10^3}\)

Questions 50 of 50

Question:The disperse phase in colloidal iron (III) hydroxide and colloidal gold is positively and negatively charged, respectivley. Which of the following statements is NOT correct

Answers Choices:

Magnesium chloride solution coagulates, the gold sol more readily than the iron (III) hydroxide sol

Sodium sulphate solution causes coagulation in both sols

Mixing the sols has no effect

Coagulation in both sols can be brought about by electrophoresis