Surface Chemistry Test 3

Total Questions:50 Total Time: 75 Min

Remaining:

Questions 1 of 50

Question:In physical adsorption, the gas molecules are held on solid surface by

Chemical forces

Electrostatic forces

Gravitational forces

Vander Waal's forces

Questions 2 of 50

Question:Adsorption is multilayer in the case of

Chemisorption

Both

None of both

Questions 3 of 50

Is irreversible in nature

Increases with increase of temperature

Questions 4 of 50

Question:The adsorption of a gas on a solid surface varies with pressure of the gas in which of the following manner

Fast$$\to$$slow $$\to$$independent of the pressure

Slow$$\to$$fast $$\to$$ independent of the pressure

Independent of the pressure $$\to$$fast$$\to$$slow

Independent of the pressure $$\to$$slow $$\to$$fast

Questions 5 of 50

Question:Which of the following statements is not applicable to chemisorption

It is slow

It is irreversible

It is highly specific

It is independent of temperature

Endothermic

Exothermic

Either 1 or 2

None of these

Questions 7 of 50

Question:Animal charcoal is used in decolourising colour of liquids because it is a good

Oxidising agent

Reducing agent

Questions 8 of 50

Question:What will be the effect of increase in temperature on physical adsorption

It will decrease

It will increase

First increase then decrease

None of these

Questions 9 of 50

Question:0.2 gm of fine animal charcoal is mixed with half litre of acetic acid solution and shaken for 30 minutes

Concentration remains same

Concentration increases

Concentration of the solution decrease

None of these

Questions 10 of 50

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

Alkali metals

Transition metals

Alkaline–earth metals

Questions 11 of 50

Question:An example of autocatalytic reaction is

The decomposition of nitroglycerine

Thermal decomposition of $$KCl{O_3}$$ and $$Mn{O_2}$$ mixture

Break down of $$_6{C^{14}}$$

Hydrogenation of vegetable oil using nickel catalysts

Questions 12 of 50

Question:In the case of auto catalysis

Solvent catalyses

Product catalyses

Reactant catalyses

Heat produced in the reaction catalyses

Questions 13 of 50

Question:Which is not a characteristic of a catalyst

It changes the equilibrium constant

It alters the reaction path

It increases the rate of reaction

It increases the average K.E. of the molecules

Questions 14 of 50

Question:Which one of the following statements is correct in reversible reaction. A catalyst

Increases the rate of forward reaction

Decreases the rate of forward reaction

Increases the rate of backward and forward reactions

Alters the equilibrium constant of the reaction

Questions 15 of 50

Question:A catalyst

Increases the free energy change in the reaction

Decreases the free energy change in the reaction

Does not increase or decrease the free energy change in the reaction

Can either increase or decrease the free energy change depending on what catalyst we use

Questions 16 of 50

Question:Protons accelerate the hydrolysis of esters. This is an example of

A heterogeneous catalysis

An acid-base catalysis

A promoter

A negative catalyst

Questions 17 of 50

Question:Which of the following processes does not involve a catalyst

Haber's process

Thermite process

Ostwald process

Contact process

Questions 18 of 50

Question:Which of the statement is wrong among the following

Haber's process of $$N{H_3}$$ requires iron as catalyst

Friedel–Craft's reaction uses anhydrous $$AlC{l_3}$$

Hydrogenation of oils uses iron as catalyst

Oxidation of $$S{O_2}$$ to $$S{O_3}$$ requires $${V_2}{O_5}$$

Questions 19 of 50

Question:Which of the following statements is incorrect

Enzymes are in colloidal state

Enzymes are catalysts

Enzymes can catalyse any reaction

Urease is an enzyme

Questions 20 of 50

Question:Enzymes are

Substances made by chemists to activate washing powder

Very active vegetable catalysts

Catalysts found in organism

Synthetic catalysts

Questions 21 of 50

Question:Catalyst used in the oxidation of $$S{O_2} \to S{O_3}$$

Nickel

$$ZnO.C{r_2}{O_3}$$

$${V_2}{O_5}$$

Iron

Questions 22 of 50

Question:Which of the following statement is wrong for lyophobic sol

Dispersed phase is generally in organic material

Can be easily coagulated by small addition of electrolyte

Dispersed phase particles are poorly hydrated and colloid is stabilised due to charge on the colloidal particles

Reversible in nature that is after coagulation can be easily set into colloidal form

Questions 23 of 50

Question:Which of the following statements is not true for a lyophobic sol

It can be easily solvated

It carries charge

The coagulation of this sol is irreversible in nature

It is less stable in a solvent

Questions 24 of 50

Question:$$A{s_2}{S_3}$$ sol has a negative charge. Capacity to precipitate it is highest in

$$AlC{l_3}$$

$$N{a_3}P{O_4}$$

$$CaC{l_2}$$

$${K_2}S{O_4}$$

Questions 25 of 50

Question:Which of the following forms a colloidal solution in water

$$NaCl$$

Glucose

Starch

Barium nitrate

Questions 26 of 50

Question:A negatively charged suspension of clay in water will need for precipitation the minimum amount of

Aluminium chloride

Potassium sulphate

Sodium hydroxide

Hydrochloric acid

Questions 27 of 50

Question:Difference between colloids and crystalloids is of

Particle composition

Particle size

Concentration

Ionic character

Questions 28 of 50

Question:Lyophilic sols are more stable than lyophobic sols because

The colloidal particles have positive charge

The colloidal particles have no charge

The colloidal particles are solvated

There are strong electrostatic repulsions between the negatively charged colloidal particles

Questions 29 of 50

Question:Which is the correct statement in case of milk

Milk is an emulsion of protein in water

Milk is an emulsion of fat in water

Milk is stabilised by protein

Milk is stabilised by fat

Questions 30 of 50

Question:Which of the following electrolytes have maximum coagulating power

$$CC{l_4}$$

$$ZnC{l_2}$$

$$KCl$$

$$NaCl$$

Questions 31 of 50

Question:Sodium stearate forms in water

True solution

A suspension

An emulsion

A colloidal solution

Questions 32 of 50

Question:Blood contains

Positively charged particles

Negatively charged particles

Neutral particles

Negatively as well as positively charged particles

Questions 33 of 50

Question:Substances whose solutions can readily diffuse through parchment membranes are

Colloids

Crystalloids

Electrolytes

Non-electrolytes

Questions 34 of 50

Question:Size of colloidal particles varies from

$${10^{ - 7}}$$ to $${10^{ - 9}}\,m$$

$${10^{ - 9}}$$ to $${10^{ - 17}}\,m$$

$${10^{ - 5}}$$ to $${10^{ - 7}}\,m$$

$${10^{ - 4}}$$ to $${10^{ - 10}}\,m$$

Questions 35 of 50

Question:For coagulating $$A{s_2}{S_3}$$ colloidal sol, which of the following will have the lowest coagulation value

$$NaCl$$

$$KCl$$

$$BaC{l_2}$$

$$AlC{l_3}$$

Questions 36 of 50

Question:Some substances behave as electrolytes in dilute solutions and as colloids in their concentrated solutions. Their colloidal forms are said to form

Emulsions

Gels

Micelles

Sols

Questions 37 of 50

Question:The shape of colloidal particles is

Sphere like

Rod like

Disc like

All of these

Questions 38 of 50

Question:Colloidal solution of arsenious sulphide is coagulated by

Addition of solid $$A{s_2}{S_3}$$

None of these

Questions 39 of 50

Question:In lyophilic sols the attraction of sol particles towards the medium is due to

Covalent bond

Vander Waal's force

Hydrogen bond

None of these

Questions 40 of 50

Question:If some gelatin is mixed in colloidal solution of gold, then it does

Coagulation of gold

Peptization of gold

Protection of gold sol

Protection of gelatin

Questions 41 of 50

Question:In Bredig's arc method some alkali is added because

It increases electrical conductance

To obtain molecular colloid

To obtain colloidal particles of same size

To stabilise the sol

Questions 42 of 50

Question:Which one of the following is not a colloid

Milk

Blood

Solution of urea

Ice cream

Questions 43 of 50

Question:Luminosity observed as a result of scattering of light by particles is observed in

Suspension

Colloidal solution

True solution

None of these

Questions 44 of 50

Question:Which of the following makes the lyophilic solution unstable

Dialysis

Addition of alcohol and electrolyte both

Questions 45 of 50

Question:The impurities present in rain water possess ..... charge

Positive

Negative

Zero

Positive and negative

Questions 46 of 50

Question:Sodium lauryl sulphate is

Cationic sol

Anionic sol

Neutral sol

None of these

Questions 47 of 50

Question:Surface tension of lyophilic sols is

Lower than that of $${H_2}O$$

More than that of $${H_2}O$$

Equal to that of $${H_2}O$$

None of these

Questions 48 of 50

Question:Which of the following is not true of a detergent molecule

It has a non-polar organic part and a polar group

It is a sodium salt of fatty acid

It is a surface active agent

Questions 49 of 50

Question:Paste is

Suspension of solid in a liquid

Mechanical dispersion of a solid in liquid

Colloidal solution of a solid in solid

None of these

Questions 50 of 50

Question:A precipitate is changed to colloidal solution by the following process