PYQSide ExamsMy practice

Surface Chemistry · Question 20

AIPMT 2007MCQEasy📈 Topic in 12% papers+4−1
1

The Langmuir adsorption isotherm is deduced using the assumption

  1. the adsorption sites are equivalent in their ability to adsorb the particles
  2. the heat of adsorption varies with coverage
  3. the adsorbed molecules interact with each other
  4. the adsorption takes place in multilayers

Answer

(1) the adsorption sites are equivalent in their ability to adsorb the particles

Solution

Assumptions of the Langmuir adsorption isotherm:

(i) The surface is uniform: all adsorption sites are equivalent, and each site holds only one molecule.

(ii) Adsorption is monolayer (unimolecular), not multilayer.

(iii) Adsorbed molecules do not interact with each other.

(iv) Hence the heat of adsorption is the same for every site and does not vary with surface coverage.

⇒ Options (2), (3) and (4) contradict these assumptions.

∴ The isotherm assumes that the adsorption sites are equivalent in their ability to adsorb the particles.

Answer: (1)

Out of syllabusAIPMT 2007

Keep practising — Surface Chemistry

2

A plot of (x/m) versus p for the adsorption of a gas on a solid gives a straight line with slope equal to

  1. K
  2. - K
  3. n
  4. 1/n
Out of syllabusAIPMT 2006
3

Which one of the following forms micelles in aqueous solution above certain concentration?

  1. Dodecyl trimethyl ammonium chloride
  2. Glucose
  3. Urea
  4. Pyridinium chloride
Out of syllabusAIPMT 2005
4

Which of the following forms cationic micelles above certain concentration?

  1. Sodium dodecyl sulphate
  2. Sodium acetate
  3. Urea
  4. Cetyltrimethylammonium bromide.
Out of syllabusAIPMT 2004
5

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

  1. the concentration of reactant molecules at the active centres of the catalyst becomes high due to adsorption
  2. in the process of adsorption, the activation energy of the molecules becomes large
  3. adsorption produces heat which increases the speed of the reaction
  4. adsorption lowers the activation energy of the reaction.
Out of syllabusAIPMT 2003
6

Position of non-polar and polar part in micelle

  1. polar at outer surface but non-polar at inner surface
  2. polar at inner surface but non-polar at outer surface
  3. distributed over all the surface
  4. are present in the surface only
Out of syllabusAIPMT 2002
7

Which is not correct regarding the adsorption of a gas on surface of a solid?

  1. On increasing temperature adsorption increases continuously.
  2. Enthalpy and entropy change is negative.
  3. Adsorption is more for some specific substance.
  4. It is a reversible reaction.
Out of syllabusAIPMT 2001
8

Which one of the following methods is commonly used for the destruction of a colloid?

  1. Dialysis
  2. Condensation
  3. Filtration by animal membrane
  4. By adding electrolyte
Out of syllabusAIPMT 2000

All Surface Chemistry PYQs →

PDFDownload Surface Chemistry PYQs as PDF Free, with answer key and a QR code to every solution — print it or study offline⬇
All NEET Chemistry chapters
Physical ChemistrySome Basic Concepts of ChemistryStructure of AtomStates of MatterThermodynamicsEquilibriumRedox ReactionsSolid StateSolutionsElectrochemistryChemical KineticsSurface Chemistry
Inorganic ChemistryClassification of Elements and Periodicity in PropertiesChemical Bonding and Molecular StructureHydrogens-Block Elementsp-Block Elements (Group 13 & 14)Environmental ChemistryGeneral Principles of Isolation of Elementsp-Block Elements (Group 15–18)d- and f-Block ElementsCoordination Compounds
Organic ChemistryOrganic Chemistry – Some Basic Principles and TechniquesIsomerismHydrocarbonsHaloalkanes and HaloarenesAlcohols, Phenols and EthersAldehydes, Ketones and Carboxylic AcidsAminesBiomoleculesPolymersChemistry in Everyday LifePrinciples Related to Practical Chemistry