A hydrogen bond is only about 5% as strong as a single covalent bond 

Explanation:

In a water molecule, the hydrogen bonds are formed between other molecules but not within the same molecule. The presence of hydrogen between molecules is intermolecular hydrogen bond and presence of hydrogen bond in the molecule itself is intramolecular hydrogen bond.

Boiling point depends on number of Hydrogen bonds not on strength of hydrogen bond so one with greater no.of Hydrogen bonds will have highest Boiling point.
H20 can form 4 Hydrogen bonds with its neighbor molecule while HF and NH3 can form only 2 such bonds.So H20 will have highest boiling point among these.

Specific heat capacity usually expressed in J.g^-1.°C^-1

Acidic nature Depends on strength of Hydrogen bond.
i.e
Acidity ∝1/Strength of HB
It is because due to greater Strength of Hydrogen bond HF cannot lose its Hydrogen molecule easily.Thats why it is least acidic.

The amount of heat required to raise the temp of one gram of substance by 1 °C or 1k is called specific heat capacity

Explanation

Although, all the options have hydrogen atoms capable of forming an intermolecular hydrogen bond. 

In option D, there is a possibility of an intra-atomic hydrogen bond. Also, the ortho placement of substituent offers a perfect opportunity for intra-atomic bonding.

The boiling points are determined by the strength of intermolecular forces:

• Water has the highest boiling point due to strong hydrogen bonding.

• Ethyl alcohol also has hydrogen bonding, but it is weaker than that of water.

• Diethyl ether has dipole-dipole interactions but no hydrogen bonding, so its boiling point is lower than water and alcohol.

• Methane has only weak London dispersion forces, resulting in the lowest boiling point.

*Water has stronger hydrogen bonds than ethyl alcohol because it forms more bonds (up to 4) and has a compact structure with highly polar*

*𝑂−𝐻 bonds. In contrast, ethyl alcohol's larger ethyl group and single -OH reduce bonding strength.*

Explanation:-

Hydrogen bond in water is 10 percent covalent due to the overlaps in the bonding orbitals and 90 percent electrostatic

Explanation:

HF forms the maximum hydrogen bonding because fluorine is the most electronegative element, creating very strong H–F···H hydrogen bonds.

Explanation:-

Water is an unusual solvent. Water has got high boiling point (100^oC), high melting point (0^oC) and high heat of vaporization (2260 J/g) when compared to other solvents. 

Heat of vaporization: The heat energy required to convert 1.0 g of a liquid at its boiling point and at atmospheric pressure into its gaseous state at the same temperature. It is a direct measure of the energy required to overcome attractive forces between molecules in the liquid phase.

Explanation

Hydrogen fluoride is the molecule formed of one hydrogen atom and one fluorine atom. Fluorine is a very electronegative compound whereas the electronegative value of hydrogen is less.

Hydrogen fluoride has a strong hydrogen bond that is present, therefore it has low volatility as compared to other Hydra acid of halogen.

One H20 molecule can form 4 Hydrogen bond with its neighbor molecule because it has 2 lone pairs.Thus average number of Hydrogen bond formed by each water molecule will be 2...So 100 molecules of water will form 200 average number of hydrogen bonds with its neighboring molecules

The evidence for the existence of hydrogen bonding has been derived from the study of the boiling points of hydrides.

Hydrides of elements like fluorine, nitrogen, and oxygen show unusually high boiling points compared to other hydrides of similar molecular weights, indicating the presence of strong hydrogen bonds. For example, water (H₂O) has a much higher boiling point than other group 16 hydrides like hydrogen sulfide (H₂S), supporting the idea that hydrogen bonding significantly contributes to the properties of these substances.

Explanation:-

Oxygen is highly electronegative than hydrogen, hence oxygen will pull the shared electron pairs in the covalent bond between O and H more towards it an with this oxygen will get a partial negative charge called δ^–. Since there are two hydrogen atoms in water molecule, there will be a total of 2δ^– charges in a single water molecule. Similarly, each hydrogen in the water molecule will bear one partial positive charge called δ⁺.

Chloroform (CHCl₃) has a hydrogen atom attached to a highly electronegative Cl, and acetone (C=O) has a lone pair on oxygen.
They form hydrogen bonds with each other, making them mutually soluble.

These liquids are called associative liquids.

The covalent bond between hydrogen and fluorine is formed by the overlap of the hydrogen s orbital and the fluorine pz orbital. The pz orbital is the only fluorine orbital that has a significant overlap with the hydrogen s orbital.

The overlap of the s and pz orbitals results in a sigma bond. The sigma bond is the strongest type of covalent bond.

Therefore, the covalent bond in HF is due to S-Pz overlapping.

The rate of water converting to vapor is slow when temperature is low, humidity is high, or there’s little air movement. Higher temperatures and surface area, along with lower humidity and increased airflow, accelerate evaporation. In such cases, more water molecules gain energy to escape into the air as vapor.

Explanation:

A hydrogen bond forms when a hydrogen atom that is covalently bonded to an electronegative atom like O, N, or F is attracted to another electronegative atom with a lone pair of electrons.

Explanation:

✅ Answer: C) Hydrogen bond

A hydrogen bond forms between two molecules, acting like a bridge connecting them through attraction between H of one molecule and an electronegative atom like O, N, or F of another.

Condition for Hydrogen Bond:
Atleast one H must be attached with most electronegative atom such as Oxygen,Flourine or Nitrogen.
In all these molecules Hydrogen is not bonded with O,F or N so thats why they cannot form HB with its own molecule.

The diameter of DNA is primarily maintained due to chemical bonds, specifically hydrogen bonds. Hydrogen bonds form between the nitrogenous bases of the DNA strands, helping to stabilize the double helix structure and maintain the overall diameter of the molecule.

HF is a weaker acid than HCl.

This is due to the strong hydrogen bonding in HF, which stabilizes the molecule and makes it less likely to release a proton compared to HCl, which dissociates more readily in solution.

hydrogen bonding occurs when hydrogen is bonded to oxygen, nitrogen, or fluorine.

These elements are highly electronegative, which allows them to attract the hydrogen atom of another molecule, resulting in a hydrogen bond. This interaction significantly influences the physical and chemical properties of compounds containing these bonds, such as increased boiling and melting points.

EXPLANATION:

The highest boiling point among H2O, NH3, and HF is H2O (water).

Hydrogen bonding is a type of chemical bond that occurs when a hydrogen atom is covalently bonded to a highly electronegative atom, such as nitrogen, oxygen, or fluorine.
It creates a strong intermolecular attraction known as hydrogen bonding. Fluorine is more electronegative than oxygen, so the hydrogen bond in HF is stronger than that in H2O.
However, H2O molecules can form hydrogen bonds with each other in a three-dimensional network while in HF, the hydrogen bond is a weaker dipole-dipole interaction.

NH3 (ammonia) also forms hydrogen bonds with its molecules, but it is a weaker hydrogen bond than in H2O.

H2O has the highest boiling point among the three because of its strong intermolecular hydrogen bonding. It takes more energy to overcome these interactions and turn the liquid into a gas, so the boiling point is higher. HF has the lowest boiling point among the three because of its weaker dipole-dipole interactions, while NH3 has a boiling point in between the other two

Hydrogen bonding plays an important role in:

• cleaning action of soaps and detergents
• adhesive action of paints and dyes
• sticking action of glue and honey

A hydrogen bond is directional.

This means that the strength and nature of the hydrogen bond depend on the orientation of the participating molecules. The hydrogen bond typically forms in a specific direction from the hydrogen atom to the electronegative atom (such as oxygen, nitrogen, or fluorine), influencing the physical and chemical properties of substances.

Explanation:

The energy required to vaporize 1 mole of a liquid is known as the molar heat of vaporisation. It is the amount of heat necessary to boil (or condense) one mole of a substance at its boiling point.

The force of attraction between partially positive charged hydrogen atom which is covalently bonded to small size , high electronegative and  active lone pair of another electronegative atom is called hydrogen bonding

Explanation:-

Steric hindrance of CH3​ and their electron donating property reduces the extent of $H$ bonding.

Therefore methanol CH3​OH forms strongest $H$ bond.

Explanation:

Ice has hydrogen bonding and covalent bond, and intermolecular hydrogen bonds are weaker than Covalent bonds. H-O are covalent bonds. H-O are intermolecular hydrogen bonding also with other neighbouring atoms.

EXPLANATION:

ethanol,water and glycerin all have hydrogen bonding b/w their molecules while chloroform has van der waal's forces. chloroform has lowest boiling point and is more volatile 

volatility ∝1/Intermolecular forces

CH₃OH: Methanol has one O-H bond, allowing for one hydrogen bond per molecule.

H₂O: Water has two O-H bonds and two lone pairs on oxygen, allowing for more extensive hydrogen bonding.

HF: Hydrofluoric acid has one H-F bond, enabling hydrogen bonding.

H₂SO₄: Sulfuric acid has two O-H bonds and several oxygen atoms with lone pairs. This provides the greatest potential for hydrogen bonding among the options.

KEYPOINT

While CH₃OH, H₂O, and HF can form hydrogen bonds, H₂SO₄ has more sites available for hydrogen bonding, leading to a greater number of hydrogen bonds overall.

specific heat of water is 4.2 J.g^-1.°C^-1

Explanation:

The magnitude of the H-bonding depends on the physical state of the compound. In the gaseous state, it is minimum and in the solid state, it is maximum. There is a great influence on a compound’s structure and properties.

HF is a weaker acid than HCl because the hydrogen atom in HF is entrapped between two highly electronegative atoms due to hydrogen bonding.

In HF, the strong hydrogen bonding between HF molecules stabilizes the molecule, making it less likely to dissociate and release a proton (H⁺) compared to HCl, where the hydrogen atom is not similarly stabilized. This results in HCl being a stronger acid because it dissociates more readily in solution.

It is due to Hydrogen bonding.

Explanation:-

The electrostatic attraction between hydrogen and the most electronegative elements of the second row is known as hydrogen bonding. The second-row element involved in hydrogen bonding are nitrogen, oxygen and fluorine.
The water has hydrogen, bonded with oxygen, so it can form hydrogen bonding. The structure of the water is as follows:

The hydrogen bonding in water is shown as follows:

The red colour bonds show the number of hydrogen bonds formed by one water molecule.
One water molecule has two hydrogen atoms which can be bonded with the oxygen of another molecule so, two hydrogen bonds are formed by hydrogen atoms. The oxygen has two lone pairs which can be donated to form two other hydrogen bonds, so a water molecule can form four hydrogen bonds.
So, the maximum number of hydrogen bonds formed by a water molecule are4.

Note: The hydrogen bonding is of two types. Intramolecular and intermolecular. Intramolecular hydrogen bonding is found between the groups within the molecule. Intermolecular hydrogen bonding is found between two groups of two molecules. Intramolecular hydrogen bonding is more stable than intermolecular hydrogen bonding. On adding a non-polar solvent the intermolecular hydrogen bonding breaks. The addition of non-polar solvent does not affect intramolecular hydrogen bonding.

Explanation:

The molar heat of vaporization is the energy required to convert 1 mole of liquid water into vapor at its boiling point.
For water, strong hydrogen bonding makes this value high, about 40.6 kJ/mol.

Explanation:

HF is weak acid because strong hydrogen bonding between HF molecules holds H⁺ tightly, making it less likely to ionize in water.

Explanation

Electronegativity is the affinity of atomic nuclei towards electrons. Each atom has specific electronegativity values, which means that they have different degree of affinity towards electrons. Oxygen, nitrogen etc. are highly electronegative atoms. The electronegativity of hydrogen is very less. When covalent bond is formed between two atoms, one with high electro-negativity and the other with lesser electronegativity, the paired electron cloud in the covalent bond will shift more towards the highly electro-negative atom and this will create a dipole in the molecule.

Book line PTB

Hydrogen bonding is present in H₂O (water) and HF (hydrogen fluoride).

Both of these molecules have hydrogen atoms bonded to highly electronegative atoms (oxygen in water and fluorine in hydrogen fluoride), allowing for strong hydrogen bonds to form between the molecules.

Explanation:

The unusual properties of water like its high boiling point, high specific heat, surface tension, and expansion on freezing are mainly due to strong hydrogen bonds between water molecules.

EXPLANATION:

Hydrogen bonding is a type of noncovalent interaction that occurs between a hydrogen atom that is covalently bonded to an electronegative atom, such as nitrogen, oxygen, or fluorine, and another electronegative atom.
In NH3 (ammonia), the nitrogen atom is electronegative and is covalently bonded to three hydrogen atoms.
These hydrogen atoms can participate in hydrogen bonding with other electronegative atoms, such as oxygen or nitrogen atoms in other molecules. This is why NH3 is a hydrogen bond acceptor.

PH3 (phosphine) and CH4 (methane) do not have any electronegative atoms that hydrogen can bond with.
SiH4 (silane) has a silicon atom which is less electronegative than Nitrogen, Oxygen or Fluorine, it is not able to participate in hydrogen bonding

Explanation:

Water (H₂O) can form 4 hydrogen bonds per molecule (2 H atoms donate, 2 lone pairs accept), which is more than NH₃ or HCl, giving it the maximum hydrogen bonding.

Explanation

Hydrogen bonds in water are highly dynamic. They life span of each hydrogen bond in water is very short. The lifetime of each hydrogen bond is just 1 to 20 picoseconds ( 1 ps = 10-12S)

a hydrogen bond is weaker than a covalent bond.

Covalent bonds involve the sharing of electron pairs between atoms and are generally much stronger, with bond energies typically ranging from 100 to 500 kJ/mol. In contrast, hydrogen bonds are a type of intermolecular force, with bond energies typically around 5 to 30 kJ/mol, making them significantly weaker than covalent bonds.

EXPLANATION:

in ice water molecules are held together by hydrogen bonding

textbook reference page # 157

Explanation:-

Even though H2O has lower molecular mass than H2Se and H2Te, but in H2O hydrogen bond exist due to which molecules get associated even at high temperature.  hydrogen bonding does not exist in H2Se and H2Te

EXPLANATION:

Hydrogen bonds do not exist in the molecule of hydrogen (H2) because hydrogen atoms do not possess a lone pair of electrons.
Hydrogen bonds are formed when a hydrogen atom that is covalently bonded to a highly electronegative atom (such as nitrogen, oxygen, or fluorine) is also attracted to another highly electronegative atom that is not bonded to the hydrogen atom.

In the case of hydrogen (H2), both hydrogen atoms are bonded to each other via a covalent bond, and there are no other highly electronegative atoms present that can attract the hydrogen atoms.
Additionally, hydrogen atoms are relatively small and do not have a large electron cloud that can participate in hydrogen bonding.

For hydrogen bond to occur, the molecule or ion should contain a hydrogen atom covalently bonded to a highly electronegative atom (N,O,F) and another highly electronegative atom should be present close by to which the hydrogen can form a weak electrostatic attraction