Surface Chemistry

15 Questions

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Surface Chemistry

Time: 30 Minute


Questions and Answers
  • 1. 
    Catalyst is required in very small non stoichiometric quantities because:
    • A. 

      They are consumed during the reaction

    • B. 

      They are not consumed during the reaction

    • C. 

      They increase the temperature of the reaction

    • D. 

      They slow down the reaction process

  • 2. 
    • A. 

      Increase in temperature

    • B. 

      Increase in pressure

    • C. 

      Decrease in temperature

    • D. 

      Decrease in pressure

  • 3. 
    Alum helps in purifying water by:
    • A. 

      Coagulating the mud particles

    • B. 

      Making mud water soluble

    • C. 

      Forming Si complex with clay particles

    • D. 

      Sulphate part which combines with dirt and removes it

  • 4. 
    The basic principle of Cottrell's precipitator is:
    • A. 

      Le Chatelier’s Principle

    • B. 

      Peptisation

    • C. 

      Neutralisation of charge on colloidal particles

    • D. 

      Scattering of light

  • 5. 
    In Freundlich Adsorption isotherm predicts a limiting adsorption at:
    • A. 

      Low pressure

    • B. 

      Intermediate pressure

    • C. 

      High pressure

    • D. 

      None of these

  • 6. 
    Chromatography is based on the principle of:
    • A. 

      Chemical adsorption

    • B. 

      Physical adsorption

    • C. 

      Hydrogen bonding

    • D. 

      Sedimentation

  • 7. 
    Identify the gas which is readily adsorbed by activated charcoal:
    • A. 

      N2

    • B. 

      O2

    • C. 

      H2

    • D. 

      SO2

  • 8. 
    Which of the following is correct for lyophilic sols:
    • A. 

      They are irreversible

    • B. 

      They are self stabilised

    • C. 

      They are readily coagulated by addition of electrolytes

    • D. 

      They are formed by inorganic substances

  • 9. 
    During the adsorption of Krypton on activated charcoal at low temperature:
    • A. 

      ΔH < 0 and ΔS < 0

    • B. 

      ΔH > 0 and ΔS < 0

    • C. 

      ΔH > 0 and ΔS > 0

    • D. 

      ΔH < 0 and ΔS > 0

  • 10. 
    Emulsifying agent is a substance which:
    • A. 

      Makes the emulsion homogeneous

    • B. 

      Helps in coagulating the emulsion

    • C. 

      Accelerates the dispersion

    • D. 

      Stabilises the emulsion

  • 11. 
    • A. 

      Irreversible reaction

    • B. 

      Heterogeneous catalysis

    • C. 

      Homogeneous catalysis

    • D. 

      Neutralisation reaction

  • 12. 
    The addition of I mL solution of 10% NaCl to 10m gold sol in the presence of 0.25 G. The gold number of starch is:
    • A. 

      0.25

    • B. 

      2.5

    • C. 

      25.0

    • D. 

      250

  • 13. 
    The most effective coagulating agent for Sb2S3 sol is:
    • A. 

      Na2SO4

    • B. 

      CaCl2

    • C. 

      Al2 (SO4)3

    • D. 

      NH4Cl

  • 14. 
    Faster coagulation of ions with high valency is explained by:
    • A. 

      Tyndall Effect

    • B. 

      Hardy-Schulze Law

    • C. 

      Freundlich law

    • D. 

      Bredig’s Arc Method

  • 15. 
    The best coagulant for the precipitation of ferric hydroxide sol is:
    • A. 

      Na3PO4

    • B. 

      NaNO3

    • C. 

      MgSO4

    • D. 

      KCl