![]() Get knowledge from this and I hope that this will be helpful. This is simply an answer that I wanted to give. Hence in case of a water molecule, the hydrogen atom will be easily to removed. Whereas in a water molecule, no methyl group is directly attached to the oxygen atom, so the polarity of the O-H bond will be greater as compared to that in methanol.(this means that the partial positive charge on hydrogen atom attached the oxygen atom will be greater as compared to that in methanol). (That is the partial positive charge on hydrogen atom will be lowered due to the presence of the methyl group) Because of its great solubility, the gas fumes in moist air. The gas is very soluble in water: at 20 C (68 F) water will dissolve 477 times its own volume of hydrogen chloride. It condenses at 85 C (121 F) and freezes at 114 C (173 F). This means that the methyl group attached to the Oxygen will increase the electron density on the oxygen atom, thereby decreasing the polarity of the O-H bond. Hydrogen chloride is a colourless gas of strong odour. And we know that all alkyl group are electron releasing group. In methanol, the oxygen atom is directly attached to the methyl group. I would simply answer directly to you main question.ġ. First of all, your question is so much confusing that no one may get what you are saying or what are you confused of. I thought that a less electron withdrawing oxygen atom would mean that the H is more negatively charged, meaning it would be stronger for hydrogen bonding, since F, O, N want more electrons as they are more electronegative? Why does a "less electron withdrawing oxygen atom" lead to a weaker hydrogen bond? Therefore the electron deficiency of the hydrogen atom is less than that of a water molecule resulting in the formation of a weaker hydrogen bond.īoth hydrogen, in methanol and water, are connected to oxygen, which has the same electronegativity and takes electrons off the hydrogen making it have a partial positive charge. I understand that both compound are able to develop hydrogen bonding, and obviously water can develop one more hydrogen bond than methanol.ĭue to presence of an electron-releasing alkyl group, the oxygen atom of an alcohol molecule is less-electron withdrawing on the remaining hydrogen atom. Liquids with stronger intermolecular interactions are usually more viscous than liquids with weak intermolecular interactions.My main question is why is the boiling point of methanol so much different from that of water? We normally think of liquids like honey or motor oil being viscous, but when compared to other substances with like structures, water is viscous. ![]() Viscosity is the property of fluid having high resistance to flow.Water has very strong intermolecular forces, hence the low vapor pressure, but it's even lower compared to larger molecules with low vapor pressures. Vapor pressure is inversely related to intermolecular forces, so those with stronger intermolecular forces have a lower vapor pressure. ![]() Water's heat of vaporization is 41 kJ/mol. Vaporization occurs when a liquid changes to a gas, which makes it an endothermic reaction. Water also has an exceptionally high heat of vaporization. Water's high surface tension is due to the hydrogen bonding in water molecules. The predicted order is thus as follows, with actual boiling points in parentheses:īesides mercury, water has the highest surface tension for all liquids. Because the boiling points of nonpolar substances increase rapidly with molecular mass, C 60 should boil at a higher temperature than the other nonionic substances. A C 60 molecule is nonpolar, but its molar mass is 720 g/mol, much greater than that of Ar or N 2O. Consequently, N 2O should have a higher boiling point. ![]() Argon and N 2O have very similar molar masses (40 and 44 g/mol, respectively), but N 2O is polar while Ar is not. A clear conclusion to be drawn from this fact is that intermolecular attractive forces vary considerably, and that the boiling point of a. Helium is nonpolar and by far the lightest, so it should have the lowest boiling point. Experience shows that many compounds exist normally as liquids and solids and that even low-density gases, such as hydrogen and helium, can be liquified at sufficiently low temperature and high pressure. To predict the relative boiling points of the other compounds, we must consider their polarity (for dipole–dipole interactions), their ability to form hydrogen bonds, and their molar mass (for London dispersion forces). The substance with the weakest forces will have the lowest boiling point.Įlectrostatic interactions are strongest for an ionic compound, so we expect NaCl to have the highest boiling point. Identify the intermolecular forces in each compound and then arrange the compounds according to the strength of those forces. (CC BY-SA 3.0 unported Sponk).Īsked for: order of increasing boiling points ![]()
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