Surface Chemistry Quiz-13

Surface Chemistry Quiz-13

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.  Catalyst :

•   Lowers activation energy
•   Increase activation energy
•   May increase or may decrease activation energy
•   Brings out equilibrium

Solution
Catalyst always lowers energy of activation. The working of negative catalyst is not based on energy of activation concept.

Q2.  Which is a homogeneous system?

•   A solution of sugar in water
•   Concrete
•   Muddy water
•   Bread

Solution
A homogeneous solution has number of phase = 1.

Q3.  The Brownian movement occurs in :

•   Colloidal solution
•   True solution
•   Suspension having size < 500 mμ
•   All of the above

Solution
Note that pollen grains also move irregularly in water, i.e., lighter and smaller suspended particles. In true solution of sugar, the sugar particles are also in motion in solution.

Q4.  In colloid particles, range of diameter is

•   1 to 100 nm
•   1 to 1000 cm
•   1 to 1000 mm1
•   1 to 100 km

Solution
In colloid particles, the range of diameters i.e.,particle size is of the order of 1 to 100 nm.

Q5. AlCl₃ in Friedel-Crafts reaction acts as :

•   Oxidizing agent
•   Reducing agent
•   Acid catalyst
•   None of these

Solution
  AlCl₃ in Friedel-Crafts reaction acts as Lewis acid to produce electrophile.

Q6.  Which is used in the Haber’s process for the manufacture of NH₃?

•   Al₂O₃
•   Fe + Mo
• CuO
•    Pt

Solution
Fe is catalyst, Mo is promoter.

Q7. The protecting power of lyophilic colloidal sol is expressed in terms of :

•   Critical miscelle concentration
•   Oxidation number
•   Coagulation value
•   Gold number

Solution
Gold number is a scale to express protecting power of lyophilic colloidal sol.

Q8. Which is not correct?

•   Every solid substance can be brought in colloidal state
•   Every solid substance can be made to behave like a lyophobic colloid
•   Addition of electrolytes coagulates the sol
•   Colloidal particles carry charges

Solution
A solid may be lyophilic or lyophobic.

Q9. Which is not shown by sols?

•   Adsorption
•   Tyndall effect
•   Flocculation
•   Paramagnetism

Solution
Rest all are characteristics of sol.

Q10.  Which is the property of hydrophilic sols?

•   High concentration of dispersed phase can be easily attained
•   Coagulation is reversible
•   The charge on particles depends on the pH of the medium and it may be positive, negative
•    All of the above

Solution
These are characteristics of hydrophilic sols.