For viscocity see https://emerginginvestigators.org/articles/on-the-relationship-between-viscosity-and-surface-tension/pdf#:~:text=Intermolecular%20forces%20play%20a%20role,that%20they%20cause%20more%20friction.

You can use Google search to find similar answers for boiing point.

Dr Ralph Nelson thank you for your contribution to the discussion

Hello Rk,

There is a relationship for viscosity with BPt within most homologous series of compounds within a range of MW, but this isn't consistent across changing chemistries or with mixtures. For instance, alkanes have a logarithmic relationship of viscosity with BPt (see attached). However, the values between alkanes and alcohols are very different, as alcohols can undergo hydrogen bonding making them more viscous.

Obviously, there's rarely a relationship between the boiling point and viscosity of a mixture, as the boiling point is largely dependent on that of each individual component and the viscosity is that of the whole.

Best

Phil

Dr Philip Rolfe thank you for your contribution to the discussion

Intermolecular forces present in a liquid are a factor which affects its viscosity. Higher the intermolecular forces, higher will be the viscosity. When there is a strong intermolecular force, the molecules of the liquids are strongly bonded to each other. This induces a resistance to move. Liquids with high intermolecular attraction have high viscosity. Hydrogen bonding and Van der Waals force of attraction are strong enough to cause high viscosity. The viscosity (thickness) of a given liquid is dependent on the strength of the intermolecular forces of attraction that are occurring between molecules of the liquid. The stronger the intermolecular forces of attraction between the molecules, the higher the viscosity of the liquid. Intermolecular forces present in a liquid are a factor which affects its viscosity. The stronger the intermolecular forces, the greater the viscosity (more thick liquid)(thickness of a liquid, a liquid's ability to flow). The weaker the intermolecular forces, the less the viscosity (less thick liquid). Intermolecular forces play a role in viscosity, because stronger attractions between molecules cause them to resist flow more strongly. Molecule size is also an important factor in viscosity because the attraction of intermolecular forces is stronger, so that they cause more friction. Low boiling liquids have stronger intermolecular forces as compared with high boiling liquids and low boiling liquids are more volatile than high boiling liquids. Both assertion and reason are correct and reason is correct explanation for assertion. Types of Molecules: the types of molecules that make up a liquid determine its boiling point. If the intermolecular forces between molecules are: relatively strong, the boiling point will be relatively high and relatively weak, the boiling point will be relatively low. Stronger intermolecular forces → molecules are more attracted to each other → they stick together better → they are harder to separate from each other. Strong IMF's lead to high boiling points, low vapor pressures, and high heats of vaporization.The stronger the intermolecular forces, the higher the normal boiling point will be. This is because with stronger intermolecular forces the energy required to separate the molecules when they are converted from liquid to gas is larger. Between two molecules of similar mass, the one with the stronger type of intermolecular force has a higher boiling point (Look for functional groups that may indicate polar molecule). Molecules with weaker intermolecular forces will generally boil at lower temperatures. We also know that the order of the strength of the intermolecular forces is ion-ion > hydrogen bonding > dipole-dipole > London forces. Ionic forces are stronger to covalent forces, which leads to the higher boiling points observed among these compounds. Water has very strong intermolecular forces, hence the low vapor pressure, but it's even lower compared to larger molecules with low vapor pressures. Viscosity is the property of fluid having high resistance to flow. The order of strength in the decreasing order is: ion-dipole, hydrogen bonds, dipole-dipole, and Vander Waals Forces. A high boiling point indicates stronger non-covalent intermolecular forces. Higher the boiling point, the higher the hydrophobic interactions, and the higher the intermolecular forces of attraction. And if the temperature of the liquid reaches the boiling point, this means that the intermolecular forces are not enough to hold together the molecules such that the phase transition to the gas phase where molecules are farther apart happens.

The stronger the intermolecular forces, the higher the normal boiling point will be. This is because with stronger intermolecular forces the energy required to separate the molecules when they are converted from liquid to gas is larger. Between two molecules of similar mass, the one with the stronger type of intermolecular force has a higher boiling point. In general, increasing intermolecular force strength produces a concomitant increase in boiling point. Looking at the same example above, ethanol ( C H3 C H2 OH ) has a boiling point of 78.37°C (173.1°F), while ethane ( C2 H6 ) has a boiling point of -89°C (-128.2°F). Low boiling liquids have stronger intermolecular forces as compared with high boiling liquids and low boiling liquids are more volatile than high boiling liquids. Both assertion and reason are correct and reason is correct explanation for assertion. Molecules with weaker intermolecular forces will generally boil at lower temperatures. We also know that the order of the strength of the intermolecular forces is ion-ion > hydrogen bonding > dipole-dipole > London forces. Molecules with a higher boiling point will have stronger intermolecular forces. The strongest intermolecular force, hydrogen bonding, will form between molecules with at least one hydrogen bonded to a highly electronegative atom, such as fluorine, nitrogen, or oxygen. Water has very strong intermolecular forces, hence the low vapor pressure, but it's even lower compared to larger molecules with low vapor pressures. Viscosity is the property of fluid having high resistance to flow. A high boiling point indicates stronger non-covalent intermolecular forces. Higher the boiling point, the higher the hydrophobic interactions, and the higher the intermolecular forces of attraction. The order of strengths of intermolecular forces is: ion-ion > H-bonding > dipole-dipole > London dispersion. Compounds with stronger intermolecular forces have higher boiling points. Intermolecular forces present in a liquid are a factor which affects its viscosity. Higher the intermolecular forces, higher will be the viscosity. When there is a strong intermolecular force, the molecules of the liquids are strongly bonded to each other. This induces a resistance to move. The viscosity (thickness) of a given liquid is dependent on the strength of the intermolecular forces of attraction that are occurring between molecules of the liquid. The stronger the intermolecular forces of attraction between the molecules, the higher the viscosity of the liquid. Intermolecular forces present in a liquid are a factor which affects its viscosity. The stronger the intermolecular forces, the greater the viscosity (more thick liquid)(thickness of a liquid, a liquid's ability to flow). The weaker the intermolecular forces, the less the viscosity. The weaker intermolecular forces mean that the molecules can more easily move past each other, or flow hence, lower viscosity. But both water and pentane are relatively small molecules. Intermolecular forces play a role in viscosity, because stronger attractions between molecules cause them to resist flow more strongly. Molecule size is also an important factor in viscosity because the attraction of intermolecular forces is stronger, so that they cause more friction.

Yes, the higher boiling liquid has stronger intermolecular forces than the lower boiling liquid. This is because it takes more energy to overcome stronger intermolecular forces and break apart the liquid into its individual molecules.

Viscosity is a measure of how resistant a fluid is to flow. Fluids with high viscosity are more difficult to pour and flow more slowly than fluids with low viscosity. Higher viscosity is generally associated with stronger intermolecular forces. This is because stronger intermolecular forces hold the fluid molecules together more tightly, making it more difficult for them to move past each other.

However, it is important to note that viscosity is also affected by other factors, such as the size and shape of the fluid molecules. For example, long, chain-like molecules tend to have higher viscosity than spherical molecules.

Here are some examples:

• Water has a higher boiling point and viscosity than ethanol, even though they have the same molecular formula. This is because water molecules can form hydrogen bonds, while ethanol molecules cannot.
• Glycerin has a higher boiling point and viscosity than water, even though it has a lower molecular mass. This is because glycerin molecules have more hydroxyl groups, which can form hydrogen bonds with each other.
• Honey has a high viscosity, even though it is a mixture of sugars and water. This is because the sugar molecules in honey are large and complex, and they can interact with each other in ways that increase the viscosity of the mixture.

Overall, higher boiling points and higher viscosities are generally associated with stronger intermolecular forces. However, it is important to consider other factors, such as the size and shape of the molecules, when comparing the viscosities of different fluids.

Dr Murtadha Shukur thank you for your contribution to the discussion

The stronger the intermolecular forces, the higher the normal boiling point will be. This is because with stronger intermolecular forces the energy required to separate the molecules when they are converted from liquid to gas is larger. Molecules with weaker intermolecular forces will generally boil at lower temperatures. We also know that the order of the strength of the intermolecular forces is ion-ion > hydrogen bonding > dipole-dipole > London forces. Water has very strong intermolecular forces, hence the low vapor pressure, but it's even lower compared to larger molecules with low vapor pressures. Viscosity is the property of fluid having high resistance to flow. The order of strengths of intermolecular forces is: ion-ion > H-bonding > dipole-dipole > London dispersion. Compounds with stronger intermolecular forces have higher boiling points. So, the melting point depends on the energy it takes to overcome the forces between the molecules, or the intermolecular forces, holding them in the lattice. The stronger the intermolecular forces are, the more energy is required, so the higher the melting point is. Temperature – pressure – The kinetic energy of the particles. – The strength of the attractions between the particles. Molecules/atoms can stick to each other. Larger and heavier atoms and molecules exhibit stronger dispersion forces than smaller and lighter ones. In a larger atom or molecule, the valence electrons are, on average, farther from the nuclei than in a smaller atom or molecule. They are less tightly held and can more easily form temporary dipoles. At low temperatures, the kinetic energy of the gas molecules becomes sufficiently low that they can no longer overcome the intermolecular forces of attraction, thus, formation of liquids. Further decrease in temperature will result in the formation of the solid phase of the substance which has the strongest IMFA. The intermolecular forces are the attractions between the molecules when temperature increases it develops more distance between molecules and because of this attraction decreases, resulting intermolecular force decreases. It decreases on heating as the particles gain energy and start vibrating. The intermolecular forces between water molecules are stronger than those between oxygen molecules. In general, the bigger the molecule, the stronger the intermolecular forces, so the higher the melting and boiling points. Intermolecular forces present in a liquid are a factor which affects its viscosity. Higher the intermolecular forces, higher will be the viscosity. When there is a strong intermolecular force, the molecules of the liquids are strongly bonded to each other. This induces a resistance to move. The viscosity of a given liquid is dependent on the strength of the intermolecular forces of attraction that are occurring between molecules of the liquid. The stronger the intermolecular forces of attraction between the molecules, the higher the viscosity of the liquid.