Surface-Chemistry-Quiz-6

Surface Chemistry Quiz-6

Dear Readers,

The one subject in NEET which is candidates who can easily attain good marks is Chemistry. That's the reason, often, one doesn’t pay notice and choose to compromise it. But if one wants to rank above others, the tip is to be thorough with NEET chemistry concepts. The understanding of reactions and definite basic understanding is what requires major attention in Chemistry but once done it only gets simpler from there. The main focus on the to-do list should be on getting a hang of the NCERT syllabus of NEET chemistry..

Q1. The catalyst used in the contact process of sulphuric acid is :

•  Copper
•  Iron
•  Vanadium pentoxide or Pt (asbestos)
•  Ni

Solution
Initially Pt asbestos was used. Now-a-days a relatively cheaper catalystis used. Also it is not poisoned by CO and.

Q2.Detergent action of synthetic detergents is due to their :

•  Interfacial area
•  High molecular weight
•  Ionisation
•  Emulsifying properties

Solution
The micelles formed by detergents in water solubilize the oily stain forming emulsion with it.

Q3.  Platinized asbestos used as a catalyst in the manufacture ofis an example of :

•   Heterogeneous catalyst
•  Autocatalyst
•  Homocatalyst
•  Induced catalyst

Solution

Q4. Tails of comets are visible due to :

•  Tyndall effect
•  Reflection
•  Brownian motion
•  None of these

Solution
Tyndall effect or scattering of light by smoke.

Q5.Which of the following is most suitable to disperse benzene in water?

•  
•  
•  
•  

Solution
  −COONa has hydrophilic (—COO) and hydrophobic moities and thus, dispersion of CHand water is possible.

Q6. Which is the wrong pair?

(i) Starch solution : sol (ii) Aq. NaCl : true solution

(iii) milk : emulsion (iv) Aq.: true solution

•  (i)
•  (iii)
• (iv)
•  (ii)

Solution
is insoluble in water and thus, it does not from true solution with water.

Q7.A catalyst for a reversible reaction is a substance that :

•  Supplies energy to the reaction
•  Decreases the time to reach equilibrium
•  Increases the equilibrium concentration of the products
•  Change the equilibrium constant of the reaction

Solution
Catalyst simply helps in attaining the equilibrium earlier.

Q8.At CMC (critical micelle concentration), the surfactant molecules undergo

•  Dissociation
•  Micelle formation
•  Both (a) and (b)
•  None of these

Solution
At critical micelle concentration, the surfactant molecules associate to form micelles

Q9.Blue colour of water in sea is due to

•  Refraction of blue light by impurities r
•  Refraction of blue sky by water
•  Scattering of light by water
•  None of the above

Solution
The colour of a colloidal solution depends on the wavelength of the light scattered by the dispersed particles, which in turn depends on the size and the nature of particle. The colour of water in sea is blue due to the scattering of light by water.

Q10. Addition ofin dilute and cold solution gives

•  Prussian blue sol
•  sol
•  Positive sol
• All of these

Solution
is Prussian blue sol of +ve charge.