SURFACE CHEMISTRY MCQs

SURFACE CHEMISTRY MCQs

The catalyst helpful and used in the lead chamber process in the oxidation of SO2 to SO3 is

  1. NO
  2. V2O5
  3. FeO
  4. Pt

NO

___ is the substance on whose surface adsorption takes place.

  1. Porous substance
  2. Absorbent
  3. Active substance
  4. Absorbate

Absorbent

Retarded reaction is that

  1. In which the rate of the reaction is independent of pressure
  2. For which ∆G is positive
  3. Which are reversible under all conditions?
  4. In which products are strongly adsorbed on the surface of the solid catalyst

In which products are strongly adsorbed on the surface of the solid catalyst

According to the Langmuir isotherm, when the pressure of the gas is very large, the adsorption

  1. Is directly proportional to pressure
  2. Is inversely proportional to pressure
  3. Is independent of pressure
  4. Is directly proportional the square of the pressure

Is independent of pressure

Which statement is true regarding chemisorption?

  1. It is monolayeric in nature
  2. It is not specific in nature
  3. It is reversible in nature
  4. It occurs at low temperature

It is monolayeric in nature

Which characteristics of adsorption is not true?

  1. Adsorption, in general increase with increase in temperature
  2. Adsorption on solids is reversible in nature
  3. Adsorption is normally selective in nature
  4. Both enthalpy and entropy of adsorption are negative

Adsorption, in general increase with increase in temperature

If θ is the fraction of the surface occupied by adsorbate molecules at equilibrium, then according to the Langmuir theory, the rate of condensation is given by

Α. a(1 – θ)p

Β. αθρ

  1. αθ
  2. a(1 – θ)

a(1 – θ)p

___ is the enrichment of chemical substances at the surface of a solid.

  1. Sorption
  2. Isotherm
  3. Adsorption
  4. Absorption

Adsorption

The kinetics of the decomposition of ammonia on the tungsten surface follows

  1. Third order
  2. First order
  3. Second order
  4. Zero order

Zero order

Which is not true for physical adsorption?

  1. It is reversible
  2. It increases with increase of P
  3. It occurs in the form of multilayer
  4. It needs activation energy

It needs activation energy

The adsorption theory can explain the action of all these except

  1. Heterogeneous catalysis
  2. Acid-base catalysis.
  3. Catalytic poisons
  4. Promoters

Acid-base catalysis

Catalytic poisons act by

  1. Making the products inert
  2. Chemical combination with any one of the reactants
  3. Increasing the rate of the backward reaction
  4. Getting adsorbed on active centers on the catalyst surface

Getting adsorbed on active centers on the catalyst surface

enthalpy change is

  1. Positive
  2. Negative
  3. Zero
  4. None of A, B, and C

Negative

Adsorption is multilayer in case of

  1. Chemical adsorption
  2. Physical adsorption.
  3. Both A & B
  4. Enzyme catalysis

Both A & B

In adsorption of methane on charcoal, charcoal is

  1. Adsorbent
  2. Adsorbate
  3. Catalyst
  4. None of A, B, and C

Adsorbent

A catalyst is a substance that

  1. Alters the reaction mechanism
  2. Increases the activation energy
  3. Increases the ave K.E. of the reactant molecules
  4. Increases the frequency of collision of reactant molecules

Alters the reaction mechanism

Spontaneous adsorption of gas on solid surface is an exothermic process, because

  1. Entropy change decreases for the gas
  2. Entropy change increase for the gas
  3. Enthalpy change increases for the system
  4. Free energy change increases for the gas

Entropy change decreases for the gas

The adsorption of a gas by metal is called

  1. Sorption
  2. Physical adsorption
  3. Chemical adsorption
  4. Occlusion

Occlusion

Which state is not true regarding Langmuir adsorption theory?

  1. Adsorption is a static process
  2. One site can adsorbs only one molecule
  3. Adsorbed molecules cannot interact with each other
  4. Adsorbent has specific equivalent sites

Adsorption is a static process

A substance which lowers the catalytic activity of a catalyst is called a/an

  1. Poison
  2. Negative catalyst
  3. Promoter
  4. Auto catalyst

Poison

A graph of extent of adsorption temperature at constant P is called

  1. Adsorption isobar
  2. Adsorption isotherm
  3. Adsorption isostere
  4. None of A, B, and C

Adsorption isobar

Dyeing of cotton is an example of Absorption

  1. Adsorption
  2. Sorption
  3. Absorption
  4. None of A, B, and C

Sorption

Which isotherm model explain chemical adsorption?

  1. Langmuir isotherm
  2. BET isotherm
  3. Freundlich isotherm
  4. None of A, B, and C

Langmuir isotherm

In the Langmuir adsorption isotherm, when p → 0, the amount of substance adsorbed per gram of the adsorbent is proportional to

  1. P
  2. 1/p
  3. p2
  4. p°

P

Pd is a good adsorbent for

  1. CO
  2. H₂
  3. SO₂
  4. CO₂

H₂

The Langmuir theory of uni molecular adsorption is normally valid at

  1. Low pressures and low temperatures
  2. High pressures and high temperatures
  3. High pressures and low temperatures
  4. Low pressures and high temperatures

Low pressures and high temperatures

The activity of a catalyst depends upon

  1. Particle size
  2. Mass
  3. Solubility
  4. None of A, B, and C

Particle size

Simultaneous occurrence of both adsorption and absorption is called _________.

  1. Sorption
  2. Physical adsorption
  3. Chemical adsorption
  4. Occlusion

Sorption

The heat of adsorption for physical adsorption is normally in what range?

  1. 100-150 kJ
  2. 40-60 kJ
  3. 20-40 kJ
  4. None of A, B, and C

20-40 kJ

Rate of physical adsorption increases with

  1. Increase in temperature
  2. Decrease in temperature
  3. Decrease in pressure
  4. Decrease in surface area

Increase in temperature

The extent of adsorption is affected by which factor(s)

  1. Surface area
  2. Temperature
  3. Pressure
  4. All of A, B, and C

All of A, B, and C

Which catalyst is helpful and used in polymerization of alkenen?

  1. (Ph3PO)3RhCl
  2. (Ph3P)3RhCl
  3. (C5H5)3Al + TICl3
  4. Rh2O3

(C5H5)3Al + TICl3

Identify the true statement

  1. A catalyst accelerate the rate of a chemical reaction
  2. A catalyst cannot start a chemical reaction
  3. A catalyst can retard the rate of a chemical reaction
  4. A catalyst controls the speed of the reaction

A catalyst accelerate the rate of a chemical reaction

A catalyst increases the rate of chemical reaction by

  1. Decreasing activation energy
  2. Decreasing internal energy
  3. Decreasing enthalpy
  4. Increasing activation energy

Decreasing activation energy

Organic catalyst differs from the inorganic catalysts in the fact that

  1. They are consumed
  2. They have no difference
  3. They are not much active
  4. They are proteins in nature

They are proteins in nature

Which process does not use a catalyst?

  1. Thermit process
  2. Ostwald process
  3. Haber process
  4. Contact process

Thermit process

Wilkinson catalyst helpful and used in hydrogenation of alkenes is?

  1. RhCl3
  2. (Ph3PO)3RhCI
  3. (Ph3P)3RhC
  4. Rh22O3

(Ph3P)3RhC

Which catalyst is helpful and used in the inversion of sucrose?

  1. (C2H5)3Al+ TiCl3
  2. Pt
  3. Xymase
  4. Invertase

Invertase

Which is less than zero during adsorption?

  1. Enthalpy change
  2. Free energy change
  3. Entropy change
  4. All of A, B, and C

All of A, B, and C

For the adsorption of gas on a solid surface, the plot of log(x/m) vs.log P is linear with slope equal to

  1. log k
  2. n
  3. k
  4. 1/n

1/n

In physical adsorption, what are the forces that are associated?

  1. van der Waals forces
  2. Covalent forces
  3. H-bonding
  4. Ionic forces

van der Waals forces

For the adsorption of gas on a solid surface, Which statement is not true?

  1. It is a reversible process
  2. Enthalpy change is negative
  3. Entropy change is negative
  4. Adsorption increases with increase in temperature

Adsorption increases with increase in temperature

Adsorption is accompanied by

  1. Decrease in the free energy of the system
  2. TAS value for the process to be positive
  3. Increase in the entropy of the system
  4. Increase in the enthalpy of the system

Decrease in the free energy of the system

The heat of adsorption for chemical is normally in what range?

  1. 20-40 kJ
  2. 1000-1500 kJ
  3. 40-400 kJ
  4. None of A, B, and C

40-400 kJ

A graph of extent of adsorption vs pressure at constant temperature is called

  1. Adsorption isotherm
  2. Adsorption isobar
  3. Adsorption isostere
  4. None of A, B, and C

Adsorption isotherm

The activation energy of a chemical reaction is lowered by

  1. Adding a catalyst
  2. Decreasing the temperature
  3. Increasing the temperature.
  4. Decreasing the P.E.

Adding a catalyst

More Physical Chemistry MCQs

  1. PHYSICAL CHEMISTRY MCQs
  2. CHEMICAL AND IONIC EQUILIBRIA MCQs
  3. NUCLEAR CHEMISTRY MCQs
  4. CHEMICAL THERMODYNAMICS MCQs
  5. NANOCHEMISTRY MCQs
  6. CHEMICAL KINETICS MCQs
  7. SURFACE CHEMISTRY MCQs
  8. COLLOIDAL STATE MCQs
  9. ELECTROCHEMISTRY MCQs
  10. SPECTROSCOPY MCQs
  11. SOLUTION CHEMISTRY AND PHASE EQUILIBRIA MCQs
  12. PHOTOCHEMISTRY AND MOLECULAR SYMMETRY MCQs
  13. CHEMISTRY MCQs From all subjects of  Chemistry
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