106
Q:

Boron cannot form which one of the following anions?

(1) BO2-

(2) BF63-

(3) BH4-

(4) B(OH)4-

A) Option 1 B) Option 2
C) Option 3 D) Option 4

Answer:   B) Option 2



Explanation:

Due to absence of low lying vacant d orbital in B, sp3d2hybridization is not possible hence BF63-will not formed. 

Subject: Chemistry
Exam Prep: AIEEE
Q:

The PCl5 molecule has trigonal bipyramidal structure. Therefore,the hybridization of p orbitals should be

A) sp2 B) sp3
C) dsp2 D) dsp3
 
Answer & Explanation Answer: D) dsp3

Explanation:

The P atom needs five orbitals to form the five P-Cl bonds. It has a 3s and three 3p orbitals, so it must use one of its 3d orbitals to form the fifth bond. These orbitals are hybridized to form five sp3d orbitals that just happen to point in the right directions to form a trigonal bipyramid.

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0 1738
Q:

Which one of the following cell organelles mainly functions as storehouse of digestive enzymes?

A) Desmosome B) Ribosome
C) Lysosome D) Vacuoles
 
Answer & Explanation Answer: C) Lysosome

Explanation:

Lysosome is found in nearly all types of eukaryotic cells (cells with a clearly defined nucleus) and is responsible for the digestion of macromolecules, old cell parts, and microorganisms. Each lysosome is surrounded by a membrane that maintains an acidic environment within the interior via a proton pump. Lysosomes contain a wide variety of hydrolytic enzymes (acid hydrolases) that break down macromolecules such as nucleic acids, proteins, and polysaccharides. So, they are known as storehouse of digestive enzymes.

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0 1123
Q:

The monomer/monomers used for the synthesis of Nylon 6 is/are

A) hexamethylenediamine and adipic acid B) caprolactam
C) urea and formaldehydeD. D) phenol and formaldehyde
 
Answer & Explanation Answer: A) hexamethylenediamine and adipic acid

Explanation:

Nylon is made when the appropriate monomers (the chemical building blocks which make up polymers) are combined to form a long chain via a condensation polymerisation reaction. The monomers for nylon 6-6 are adipic acid and hexamethylene diamine

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0 1192
Q:

Which of the following pairs is INCORRECT?

I. Haematite : Iron

II. Pitchblende : Copper

III. Monazite : Thorium

A) Only I B) Only II
C) Only I and Only II D) Only I and Only III
 
Answer & Explanation Answer: B) Only II

Explanation:
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0 15143
Q:

What are isobars?

A) Elements with same atomic number but different mass number B) Elements with different atomic number but same mass number
C) Elements with different atomic number and different mass number D) Elements with same atomic number and same mass number
 
Answer & Explanation Answer: B) Elements with different atomic number but same mass number

Explanation:
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0 1000
Q:

Which of the following is most important for absorption of heat radiated from the Sun as well as from the Earth?

A) Carbon dioxide B) Oxygen
C) Carbon monoxide D) Nitrogen
 
Answer & Explanation Answer: A) Carbon dioxide

Explanation:
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0 1008
Q:

Which one of the following statements is not correct?

 

A) Fischer projection represents the molecule in an eclipsed conformation B) Newman projection can be represented in eclipsed, staggered and skew conformations
C) Fischer projection of the molecule is its most stable conformation D) In Sawhorse projections, the lines are inclined at an angle of 120 deg to each other.
 
Answer & Explanation Answer: C) Fischer projection of the molecule is its most stable conformation

Explanation:

Fischer projections were originally proposed for the depiction of carbohydrates and used by chemists, particularly in organic chemistry and biochemistry.A Fischer projection always uses an eclipsed conformation. A Newman diagram can represent either an eclipsed conformation or a staggered conformation or a skew conformation.

 

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0 21250
Q:

In which of the following, functional group isomerism is not possible?

 

A) Alcohols B) Aldehydes
C) Alkyl halides D) Cyanides
 
Answer & Explanation Answer: C) Alkyl halides

Explanation:

The haloalkanes (also known as halogenoalkanes or alkyl halides) are a group of chemical compounds derived from alkanes containing one or more halogens.Halogens can’t form more than one bond in the context of common organic compounds and can’t form multiple bonds to carbon.

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