Surface Chemistry Quiz-12

Surface Chemistry Quiz-12

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.  Which graph is correct for critical micelle concentration (CMC)?

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Solution

Q2.  Gold number gives

•   The amount of gold present in the colloid
•   The amount of gold required to protect the colloid
•   The amount of gold required to break the colloid
•   None of the above

Solution
Gold number is defined as “the minimum amount of protective colloid in milligrams required to just prevent the coagulation of a 10 mL of a given gold sol, when 1 mL of a 10% solution of sodium chloride is added to it.

Q3.  Micelle is a term used for the aggregates formed in solution by

•   Colloidal electrolyte
•   Colloidal non-electrolyte
•   Non associated colloids
•   None of the above

Solution

Q4.  Gelatin is often used as an ingredient in the manufacture of ice-cream. The reason for this is :

•   To prevent the formation of a colloid
•   To stabilize the colloid and prevent crystal growth
•   To cause the mixture to solidify
•   To improve the flavour

Solution
Gelatin is protective colloid.

Q5. Which one of the following is a property of physisorption?

•   None-specific nature
•   High specificity
•   Irreversibility
•   All of these

Solution
 

Q6.  Which characteristic is the most important factor in giving rise to peculiar properties of colloids?

•   Large size
•   Small size
• High charge density
•   High ratio of surface are to the volume

Solution
Colloidal state possesses lower surface tension or increase in surface area. This provides sol to acquire peculiar properties, e.g., more adsorption power.

Q7. Negative catalyst or inhibitor is one :

•   Which retards the rate of reaction
•   Takes the reaction in forward direction
•   Promotes the side reaction
•   None of the above

Solution
The definition of negative catalyst.

Q8. Choose the incorrect statement

•   If the mutual affinity between the dispersed phase and the dispersion medium is small, the system will be lyophobic
•   If the mutual affinity between the dispersed phase and dispersion medium is great, the system will be lyophilic
•   In a system, when water is the dispersion medium, the system may be hydrophobic or hydrophilic
•   Ionic surfactant molecules cluster together in clumps

Solution
Ionic surfactant molecules are preferentially adsorbed at the interfaces

Q9. The separation of colloidal particles (or purification of sol) from particles of molecular dimensions is known as :

•   Photolysis
•   Dialysis
•   Pyrolysis
•   Peptization

Solution
It is the definition of dialysis.

Q10.  Dust storm is :

•   Dispersion of solid in gas
•   Dispersion of a gas in solid
•   Dispersion of solid in solid
•   Dispersion of a gas in liquid

Solution
Dust storm is solid dispersed in gas, a class (solid aerosol) of colloidal system.