Sawaal
107
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
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White phosphorus undergoes spontaneous combustion when exposed to air. In order to prevent this spontaneous ignition, it is preserved under water. 

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Which of the following is called 'the King of Chemicals' ?

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Explanation:

Sulphuric acid is called the King of Chemicals because it is used in the preparation of a very large number of other useful chemicals such as hydrochloric acid, nitric acid, dyes, drugs etc. In fact the annual production of shulpuric acid in a country is a measure of the economy of the country.

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According to the modern Periodic Law, the properties of elements are periodic functions of their

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Q:

Washing soda is 

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7 5005
Q:

The enzyme in whosepresence glucose and fructose are converted into alcohol is 

A) Diastase B) Maltase
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1 2428
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When formaldehyde and potassium hydroxide are heated , we get 

A) Acetylene B) Methyl alcohol
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Explanation:
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147 24357
Q:

The atoms of the elements having same atomic number but different mass number are called

A) Isobar B) Isotopes
C) Iso electronic D) Isotones
 
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Explanation:
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4 3299
Q:

An atom has 7 electrons in its M - shell and contains 18 neutrons in its nucleus. What is its mass number

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Explanation:

According to Bohr model, Each shell can occupy 2n2 electrons in their orbits where n=1,2,3.. for K,L,M,..

 

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