# 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

Absorber

## Questions 2 of 50

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

Absorption

Chemisorption

Desorption

## Questions 3 of 50

Question:The charge on colloidal particles is due to

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

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

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

$${P^0}$$

$$P$$

$${P^n}$$

$${P^{1/n}}$$

## Questions 7 of 50

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

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

Oxidation

Reduction

Bleaching

## Questions 9 of 50

Question:Mark the correct statement in a reversible reaction

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

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

Copper

Iron/aluminium oxide

Platinized asbestos

## Questions 12 of 50

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

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

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

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

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

$$Mo$$

$$Fe$$

$$Ni$$

$$Pt$$

## Questions 17 of 50

Question:A biological catalyst is essentially

An amino acid

A carbohydrate

The nitrogen molecule

An enzyme

## Questions 18 of 50

Question:A catalyst added to a reaction mixture

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

Acid-base catalysis

Autocatalysis

Negative catalysis

None of these

Platinum

Iron

Molybdenum

Nickel

## Questions 21 of 50

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

$$KCl$$

$$KN{O_3}$$

$${K_2}S{O_4}$$

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

## Questions 22 of 50

Question:Sky looks blue due to

Dispersion effect

Reflection

Transmission

Scattering

## Questions 23 of 50

Question:The stability of lyophilic colloids is due to

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

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

Emulsification properties

Hydrolysis

Ionization

High molecular weight

## Questions 26 of 50

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

Sol

Aerosol

Organosol

Aquasol

## Questions 27 of 50

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

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

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

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

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 $$AgI$$

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

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

Diffusion

Peptization

Tyndall effect

Brownian movement

## Questions 34 of 50

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

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

0.585

0.0585

0.1

One

## Questions 36 of 50

Question:Which one is an example of miceller system

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

Peptization value

Gold number

Flocculation value

## Questions 38 of 50

Question:Milk is

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

Colloids

Gas equation

Kinetic energy

## Questions 40 of 50

Question:Small liquid droplets dispersed in another liquid is called

Gel

Emulsion

Suspension

True solution

## Questions 41 of 50

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

Dialysis

Condensation

By ultrafiltration

## Questions 42 of 50

Question:Which is a colloid

Sugar solution

Urea solution

Silicic acid

$$NaCl$$ solution

## Questions 43 of 50

Question:Alum helps in purifying water by

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

$$N{a^ + }$$

$$B{a^{ + + }}$$

$$A{l^{ + + + }}$$

$$S{n^{ + + + + }}$$

## Questions 45 of 50

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

Starch

Gum

Gelatin

Metal sulphide

## Questions 46 of 50

Question:Hydrophilic sols are

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

Absorption

Emulsification

Coagulation

None of these

## Questions 48 of 50

Question:Lyophilic sols are

Irreversible sols

They are prepared from inorganic compound

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

$$\frac{{{V_C}}}{{{V_S}}}\tilde --1$$

$$\frac{{{V_C}}}{{{V_S}}}\tilde --{10^{23}}$$

$$\frac{{{V_C}}}{{{V_S}}}\tilde --{10^{ - 3}}$$

$$\frac{{{V_C}}}{{{V_S}}}\tilde --{10^3}$$

## 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