Chemistry

Chemical Bonding and Molecular Structure

1,277 Questions

This section tests your knowledge of chemical bonding, molecular structure, and hybridization. It covers ionic and covalent bonds, octet rule exceptions, and molecular geometry. These chemistry questions are common in various competitive entrance examinations.

Ionic and covalent bondsHybridisation of elementsOctet rule exceptionsMolecular geometryIntermolecular forces

Chemical Bonding and Molecular Structure Questions

Multiple choice polyhalogen compounds haloalkanes and haloarenes chemistry

Which of the following is used in paint removing ?

  1. $CHCl _{3}$
  2. $CH _{2}Cl _{2}$
  3. $CCl _{4}$
  4. $CH _{3}Cl$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$CHCl _3$ is used as solvent and as an anaesthetic.

$CCl _4$ is used as a fire extinguisher.
$CH _2Cl _2$ is used as paint removing.
$CH _3Cl$ is used as a refrigerant.

Hence, the correct option is B.

Multiple choice isomerism of amines organic compounds with functional group containing nitrogen

Amongst the following, the strongest base in aqueous medium is ____________. 

  1. $CH _3NH _2$
  2. $NCCH _2NH _2$
  3. $(CH _3) _2NH$
  4. $C _6H _5NHCH _3$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

${2}^{0}$ amine is strongest base in aqucous media.

order of basicly in aq. media  ${ 2 }^{ 0 }>{ 1 }^{ 0 }>{ 3 }^{ 0 }$ (amines)
in gaseous phase it is ${ 3 }^{ 0 }>{ 2 }^{ 0 }>{ 1 }^{ 0 }$ (amines)

Multiple choice isomerism of amines organic compounds with functional group containing nitrogen

Which of the following statements concerning cyclic amines is correct?

  1. they can never be primary amines

  2. they are mostly aromatic compounds

  3. they can be primary or secondary amines but never tertiary amines

  4. they are only found as naturally-occurring compounds
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Cyclic amines can never be primary amines, as their valency is already satisfied (2 of its valency) by the carbon chain.

Multiple choice isomerism of amines organic compounds with functional group containing nitrogen

What is the basis for classifying amines as primary, secondary, or tertiary?

  1. The number of carbon atoms bonded directly to the nitrogen atom

  2. The number of carbon atoms bonded to a carbon bearing nitrogen

  3. The number of nitrogen atoms present

  4. The number of hydrogen atoms present
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Basic criteria for classifing amines as primary, secondary or tertiary is that chow much number of carbon atom bonded directly nitrogen atom.

If three carbon directly attached then ${ 3 }^{ 0 }$ amine
If two carbon directly attached then ${ 2 }^{ 0 }$ amine
If one carbon directly attached then ${ 1 }^{ 0 }$ amine

Multiple choice isomerism of amines organic compounds with functional group containing nitrogen

Which of the following is a secondary amine ?

  1. $CH _3CH _2NH _2$
  2. $CH _3CH _2N(CH _3) _2$
  3. $CH _3CH _2NHCH _3$
  4. $CH _3CH _2H _2CNH _2$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

$CH _3CH _2NHCH _3$ is a secondary amine. Secondary amines have one hydrogen atom and two alkyl or aryl groups attached to the nitrogen. 

Hence option C is correct.

Multiple choice isomerism of amines organic compounds with functional group containing nitrogen

Which of the following is the primary amine :

  1. $CH _3NH _2$
  2. $CH _3NHCH _3$
  3. $(CH _3) _3N$

  4. None
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$CH _3NH _2$ is primaryamine. Primary amines  have two hydrogen atoms and one alkyl or aryl group attached to the nitrogen to form the amine or amino group $NH _2$. Hence option A is correct.

Multiple choice isomerism of amines organic compounds with functional group containing nitrogen

Ethyl dimethyl amine is :

  1. tertiary amine

  2. primary amine

  3. secondary amine

  4. None
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Ethyl dimethyl amine is tertiary amine.Ethyl dimethyl amine have no hydrogen atom and three alkyl or aryl groups attached to the nitrogen. tertiary amines have no hydrogen atom and three alkyl or aryl groups attached to the nitrogen. Hence option A is correct.

Multiple choice isomerism of amines organic compounds with functional group containing nitrogen

The elements present in a tertiary amine with two phenyl groups are:

  1. carbon and nitrogen

  2. carbon, nitrogen and hydrogen

  3. carbon, nitrogen and oxygen

  4. carbon, nitrogen, hydrogen and oxygen
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Tertiary amine has 3 carbon atoms bonded directly to the nitrogen atom
Thus the elements are carbon, nitrogen and hydrogen.
Multiple choice chemistry patterns and properties of metals periodic trends in chemical properties alkali metals study of specific groups

Which of the following does not react with water?

  1. Sodium ions

  2. Sodium atoms

  3. Potassium ions
  4. Both $A$ and $C$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Sodium ions and potassium ions do not react with water.
The main reason is that have already lost that electron and are therefore much more stable. They don't tend to lose another electron, and they certainly don't try to get that lost electron back, so there's no tendency for them to react.

Multiple choice chemistry patterns and properties of metals periodic trends in chemical properties alkali metals study of specific groups

Metal cation ionic solids dissolve in solution exothermically.This is best explained by which of the following?

  1. The hydrogen bonding in the water break apart, releasing large amounts of energy that are used to force a breaking of the ionic structure.

  2. The free floating electrons in the metal cations provide a large measure of electricity when the ionic solid is broken down in the water.

  3. The breaking of the ionic structure, which releases bond energy causing the solution to be exothermic.

  4. The attraction of the cations and anions to the dipoles in water, resulting in a release of energy.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Metal cationic  solids dissolve in solution exothermally due the free floating of electrons in the metal cations provide a large measure of electricity when the ionic solid is broken done in the water.

Hence option B is correct.