Hydrogen Bonding MCQ Quiz in मल्याळम - Objective Question with Answer for Hydrogen Bonding - സൗജന്യ PDF ഡൗൺലോഡ് ചെയ്യുക

Concept:

Hydrogen bonding:

• It is the electrostatic attraction between hydrogen atoms bonded to small, strongly electronegative atoms (N, O, and F).
• The bonding occurs through the lone pair of electrons on the electronegative atoms.
• Example: HF, H₂O, etc.

2 Types of Hydrogen bonding:- Intermolecular and Intramolecular H-bonding.

• Intermolecular: Hydrogen bond formed between 2 molecules.
• Intramolecular: Hydrogen bond formed between two different atoms of the same molecule.
• Intermolecular Hydrogen bonding is stronger than van der waals' forces. 

The essential requirement of Hydrogen bonding:

1. An H atom must be directly bonded to a highly electronegative atom.

2. Lone pair of electrons must be present on the electronegative atom.

Factors affecting Hydrogen bonding:

1. Association

Due to intermolecular H-bonding, carboxylic acid exists as dimers even in the vapor state.

2. Higher Boiling and Melting point

• Compounds having H-bonding requires larger energy to separate the molecules before they can melt or boil.
• So, the compounds containing H-bonds have high melting and boiling points.

3. Physical state 

Explanation:

The difference in characteristics between NH₃ and PH₃ is given below:-

• Due to the lesser electronegativity of PH₃ molecules, they cannot form H-bonding.
• PH3 can H-bond with water only but not with itself.
• Although PH₃ is larger than NH₃ with greater dispersion forces, NH₃ has a higher polar N--H bond which gives rise to H-bonding.
• Since the strength of the H-bond is greater than the dispersion forces, the boiling point of NH₃ is greater.

The hydrogen bonding in NH₃ is shown below:

Hence, NH3 has a much higher boiling point than PH3 because NH3 forms hydrogen bond.

Concept:

Hydrogen bonding:

• Hydrogen bonding is a special type of interaction that occurs between a hydrogen atom bonded covalently to an electronegative atom and another highly electronegative atom in the vicinity of this hydrogen.
• It is a special type of dipole-dipole interaction.
• Although H-bond is very weak but compounds having H-bond have high melting and boiling point.

There are two types of H-bonding -

1. Intermolecular H-bonding
2. Intramolecular H-bonding

→ Only small size and highly electronegative atoms are capable of forming H-bond with Hydrogen. 

Explanation:

The hydrogen bond is a special type of bond between a hydrogen atom bonded covalently to an electronegative atom and another highly electronegative atom in the vicinity of this hydrogen.

→ Condition for H-Bonding :

Only small size and highly electronegative atoms are capable of forming H-bond with Hydrogen.

∴ only F, O, and N are such atoms that can make an H-bond with the hydrogen of other molecules.

In the given compounds HCl, H2O, HI, and H2S only H2O can form H-bond because Cl, S, and I are large size atoms and cannot form H-bond.

∴ Only H₂O will form H-bond 

• Intermolecular H-bonding is there in the water.
• Each H₂O can make four H-bonds. Two with O-atom and two with H-atom.
• Each H₂O molecule is tetrahedrally linked to the four other H₂O molecules.

Conclusion:

Therefore, H-bonding will be strongest in H₂O.

Hence, the correct answer is option 2.

Concept:

Hydrogen bonding:

• Hydrogen bonding is a special type of interaction that occurs between a hydrogen atom bonded covalently to an electronegative atom and another highly electronegative atom in the vicinity of this hydrogen.
• It is a special type of dipole-dipole interaction.
• Although H-bond is very weak but compounds having H-bond have high melting and boiling point.

There are two types of H-bonding -

1. Intermolecular H-bonding
2. Intramolecular H-bonding

→ Only small size and highly electronegative atoms are capable of forming H-bond with Hydrogen. 

Explanation:

The hydrogen bond is a special type of bond between a hydrogen atom bonded covalently to an electronegative atom and another highly electronegative atom in the vicinity of this hydrogen.

→ Condition for H-Bonding :

Only small size and highly electronegative atoms are capable of forming H-bond with Hydrogen.

∴ only F, O, and N are such atoms that can make an H-bond with the hydrogen of other molecules.

In the given compounds HCl, H2O, HI, and H2S only H2O can form H-bond because Cl, S, and I are large size atoms and cannot form H-bond.

∴ Only H₂O will form H-bond 

• Intermolecular H-bonding is there in the water.
• Each H₂O can make four H-bonds. Two with O-atom and two with H-atom.
• Each H₂O molecule is tetrahedrally linked to the four other H₂O molecules.

Conclusion:

Therefore, H-bonding will be strongest in H₂O.

Hence, the correct answer is option 2.

Concept:

Intermolecular hydrogen bonding: 

• This type of bonding mainly occurs between two or more same or different molecules when they combine to form a dimer or polymer respectively and leads to a phenomenon known as an association.
• Such a type of hydrogen bonding increases the boiling point of the compound and also its solubility in water. 

Intramolecular hydrogen bonding: 

• This type of bonding occurs within two atoms of the same molecule and leads to a phenomenon known as chelation.
• This type of hydrogen bonding frequently occurs in organic compounds and results in the cyclization (six or five-membered ring) of the molecule. 

Explanation:

• o-nitrophenol has intramolecular hydrogen bonding so it is more volatile.
• So, the statement I is true.
• The lowest melting point of o-isomer is due to intramolecular hydrogen bonding whereas meta and para isomers possess intermolecular hydrogen bonding and thus, they have higher melting points. 
• Thus statement II is false.​

Correct Answer: (3)

Concept:

Hydrogen bonding:

• It is the electrostatic attraction between hydrogen atoms bonded to small, strongly electronegative atoms (N, O, and F).
• The bonding occurs through the lone pair of electrons on the electronegative atoms.
• Example: HF, H₂O, etc.

2 Types of Hydrogen bonding:- Intermolecular and Intramolecular H-bonding.

• Intermolecular: Hydrogen bond formed between 2 molecules.
• Intramolecular: Hydrogen bond formed between two different atoms of the same molecule.
• Intermolecular Hydrogen bonding is stronger than van der waals' forces. 

The essential requirement of Hydrogen bonding:

1. An H atom must be directly bonded to a highly electronegative atom.

2. Lone pair of electrons must be present on the electronegative atom.

Factors affecting Hydrogen bonding:

1. Association

Due to intermolecular H-bonding, carboxylic acid exists as dimers even in the vapor state.

2. Higher Boiling and Melting point

• Compounds having H-bonding requires larger energy to separate the molecules before they can melt or boil.
• So, the compounds containing H-bonds have high melting and boiling points.

3. Physical state 

Explanation:

The difference in characteristics between NH₃ and PH₃ is given below:-

• Due to the lesser electronegativity of PH₃ molecules, they cannot form H-bonding.
• PH3 can H-bond with water only but not with itself.
• Although PH₃ is larger than NH₃ with greater dispersion forces, NH₃ has a higher polar N--H bond which gives rise to H-bonding.
• Since the strength of the H-bond is greater than the dispersion forces, the boiling point of NH₃ is greater.

The hydrogen bonding in NH₃ is shown below:

Hence, NH3 has a much higher boiling point than PH3 because NH3 forms hydrogen bond.