All Questions
Tagged with intermolecular-forces boiling-point
47 questions
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What explains the relative order of melting and boiling of oxygen and nitrogen?
Why is the melting point of nitrogen ($\ce{N2}$) greater than that of oxygen ($\ce{O2}$)? After all, both are non-polar, and $\ce{O2}$ has more electrons than $\ce{N2}$.
In addition, why is the ...
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1
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1
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Why does AsH3 have a higher boiling point than HBr?
Aside from the general trend of the boiling points of the hydrides, I noticed how the group 15 hydrides somehow "overtook" the group 17 ones in boiling point, which felt weird.
Notably, H-...
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Why is octane more volatile than water while having a higher boiling point?
Octane has a boiling point of 120 °C. Water has a boiling point of 100 °C. The definition of boiling point is, "the temperature which the liquid substance's saturated vapor pressure equals the ...
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Why does N,N-dimethylethanamide have a higher boiling point than butanoic acid?
According to Wikipedia, N,N-dimethylethanamide has a boiling point of $\pu{165.1 °C},$ while butanoic acid has a boiling point of $\pu{163.75 °C}.$
From what I learned, butanoic acid should have a ...
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Is there experimental evidence to show boiling point increases with external electric field, and if so, by how much?
I was wondering whether anyone has demonstrated that a liquid will have a higher boiling point if it is placed in a very large electric field. I believe to be the case, since induced dipoles would be ...
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Why do some hydrates need to be heated over 100 Celsius to evaporate the water?
If the boiling point of water is at 100 °C, why does a hydrate need to be heated higher than that to evaporate water from the crystals? Does it have anything to do with their intermolecular forces?
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Why does alkylamines have a higher boiling point than ammonia?
Here are the boiling points of ammonia and some amines:
$$ \begin{array}{|c|c|}
\hline
\textrm{Substance} & \textrm{Boiling Point} \\
\hline
\textrm{Ammonia} & \pu{-33.34^\circ C} \\
\textrm{...
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21
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1
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Why is the boiling point of fluorine lower than that of oxygen?
Fluorine boils at -188.1 °C and oxygen boils at -183 °C, but shouldn't $\ce{F2}$ boil after $\ce{O2}$?
Despite being electronegative elements, both are nonpolar molecules and posses dispersion forces ...
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What happens to the sea of electrons when a metal melts/boils? [closed]
I was taught about metallic solids with the sea of electrons model. My question is how does the sea of electrons function when metal turns into a liquid and a gas. The way I see a liquid is ...
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Why do fluoride molecules seem to have abnormally low boiling points?
As far as I know, to non-polar molecules like CF4 and C2H6,
boiling point is mainly affected by the London dispersion force.
As a result, molecules with more protons and electrons normally have higher ...
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Intermolecular forces of attraction between positional isomers of alcohols
This seemingly trivial question is as follows: Why is the boiling point of 1-butanol ($\ce {117.7 ^\circ C}$) higher than that of 2-butanol ($\ce {99 ^\circ C}$)?
The only reason I can think of is ...
- 10.8k
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Why does Ethylene Glycol have higher boiling point than Propylene Glycol?
Looking at the two alcohols, both have hydrogen bonding and are singly bonded throughout the molecule. However, propylene glycol has a larger electron cloud which to my knowledge would increase its ...
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Why ethyl cyanide and propanol have the same boiling point?
As I understand, the intermolecular forces of ethyl cyanide are of van der Waals nature (dipole-dipole) but in the propanol molecule there are hydrogen bonds which are in principle much stronger. Why ...
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Why hydrogen bonds are stronger than Van der Waals forces?
Why the hydrogen bonds are more intense than Van der Waals forces in the case where the molecules with the Van der Waals forces have a stronger dipolar moment than the molecules with the hydrogen bond?...
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Anomalous boiling point of "iso-" alkanes
I was attempting to compare the boiling points of iso-hexane and 3-methylpentane.
Boiling points of organic compounds depend upon three factors according to Master Organic Chemistry – 3 Trends That ...
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Why is the boiling point of ethyl fluoride lower than that of hydrogen fluoride?
The book, Solomons' Organic Chemistry (for JEE Mains and Advance), contains the following question:
Hydrogen fluoride has a dipole moment of $\pu{1.82 D}$; its boiling point is $\pu{19.34 ^{\circ} ...
user88957
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Boiling points of ethylene, formaldehyde and oxygen
The boiling points of ethylene, formaldehyde and dioxygen are $\pu{-103.7 ^\circ C}$, $\pu{-19 ^\circ C}$, and $\pu{−183 ^\circ C}$, respectively. I expect formaldehyde to have the highest boiling ...
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Which has a lower boiling point, Ozone or CO2? Why?
Ozone is a bent molecule, and therefore, Ozone is a polar molecule.
Polar molecules have dipole-dipole intermolecular forces.
CO2 is a linear molecule, and therefore, CO2 is a nonpolar molecule.
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Why don’t compounds with high boiling points not necessarily have high attraction constants (a) in the Van der Waals equation?
You can find a list of constants $a$ and $b$ for the van der Waals equation in a Wikipedia website. Accordingly, hexane has a higher attraction constant ($a$) than that for water (24.71 vs 5.536), but ...
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Why does chlorine gas have a higher boiling point than hydrogen iodide
Hydrogen iodide, $\ce{HI}$, is a dipolar molecule much larger than chlorine, $\ce{Cl2}$.
The melting point of $\ce{HI}$ $(222.35\ \mathrm K)$ is definitely higher than that of $\ce{Cl2}$ $(171.6\ \...
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Why are the dispersion forces in CS2 stronger than the dipole-dipole forces in COS?
London dispersion forces supposedly have the least strength out of all the intermolecular forces. But $\ce{CS2}$, which has only dispersion forces, has a higher boiling point (and thus stronger ...
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Boiling point of ethanamide vs propanamide
I just have a question regarding the boiling points of some primary amides. Ethanamide has a boiling point of 222 °C, while propanamide has a lower boiling point of 213 °C. Both amides are capable of ...
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1
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What effect on boiling and melting points does intramolecular hydrogen bonding have? [duplicate]
I know that intermolecular forces increase the boiling and melting point of a compound, but what is the effect of intramolecular forces on boiling and melting points?
I found contradicting answers ...
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2
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How can I determine the highest boiling point given a list of molecules? [closed]
I know that the highest boiling point has to do with which has the strongest intermolecular force. I also know that the strongest would be ionic, then hydrogen bonding, then dipole-dipole, then london ...
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1
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Why does Xe have a higher boiling point than Ne? [duplicate]
I am certain that the reason involves intermolecular forces, but since both $Xe$ and $Ne$ are noble and non-polar gases, shouldn't these forces have a much smaller effect or negligible on boiling ...
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Why do alkanes have higher boiling point than their ether counterparts?
Based on my understanding of intermolecular forces, I expect dipole-dipole interactions to be significantly stronger than van der Waals' interactions. Hence, I expect ethers (which obviously have ...
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Why is the boiling point of polonium less than that of tellurium?
My textbook states that polonium has a lower boiling point than tellurium because it has weaker intermolecular forces of attractions (van der Waals forces).
Why are van der Waals forces of attraction ...
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Why is the boiling point of hydrogen sulfide higher than that of hydrogen chloride?
The boiling point of $\ce{H_2S}$ is higher than $\ce{HCl}$. Is this due to the greater number of hydrogen bond that $\ce{H_2S}$ can form compared to $\ce{HCl}$? I found this explanation for the ...
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Chemical bonding [duplicate]
How do we compare the strength of permanent dipole permanent dipole (PDPD) interaction? Is it by bond polarity?
Since H-X (where X is halogen) is polar, and for bond polarity (PDPD bond strength): ...
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Ordering compounds by boiling points
Here is a MC question from my chemistry professor:
What is the correct order of boiling points for molecules: $\ce{CO2}$, $\ce{LiOH}$, $\ce{CH3OH}$, $\ce{CH2O}$?
I am mainly confused about ...
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Why do alkenes with more surface contact have greater London forces?
Why is it that alkenes with greater surface contact have greater London forces? I thought greater London forces were dependent on the size of the molecules, or the number of electrons, rather than the ...
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1
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Why do alcohols and ethers have approximately the same solubility in water but different boiling points?
In Morrison & Boyd, I found this question:
Butan-1-ol (b.p. $118~\mathrm{^\circ C}$) has a much higher boiling point than its isomer diethyl ether (b.p. $35~\mathrm{^\circ C}$), yet both ...
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Why does CO2 have higher boiling point than CO?
The intermolecular forces between $\ce{CO2}$ molecules are dispersion forces, while the forces between $\ce{CO}$ molecules are mostly dipole-dipole attraction forces. So, why does $\ce{CO2}$ have a ...
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Why does chlorine have a higher boiling point than hydrogen chloride?
Chlorine has a boiling point of $238~\mathrm{K}$ while hydrogen chloride has a boiling point of $188~\mathrm{K}$.
Hydrogen chloride has dipole-dipole forces so I would expect it to have greater inter-...
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Trend in the boiling point of the hydrogen halides
The boiling points of the hydrogen halides are as follows:
$$\begin{array}{cc}
\hline
\text{Species} & \text{Boiling point / }\mathrm{^\circ C} \\
\hline
\ce{HCl} & -85.1 \\
\ce{HBr} & -...
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Why do chlorinated silanes have lower boiling points than their methane analogs?
The boiling points of the chlorinated silanes and methanes are given below:
$$\begin{array}{ccc}
\hline
\text{Species} & \text{Boiling point (X = Si) / }\mathrm{^\circ C} & \text{Boiling ...
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Why is the boiling point of CH3COOH higher than that of C2H5OH?
Why is the boiling point of $\ce{CH3COOH}$ higher than that of $\ce{C2H5OH}$ ? Both are polar molecules held by hydrogen bond.
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What is the connection between vapor pressure and intermolecular force explanations of boiling?
I've had boiling explained to me in two ways, and I'm having trouble understanding how they connect.
The first way is that a liquid is held together by the intermolecular forces, and boiling involves ...
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Alkane, alkene, alkyne boiling point comparison
Which of the following has higher boiling points? Alkanes, alkenes, or alkynes? And why?
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Reason for the formation of azeotropes
Why is it that some liquid mixtures (that exhibit positive/negative deviation from Raoult's law) form azeotropic mixtures at certain compositions? What is the physical reason behind this; are there ...
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Melting and boiling points of benzene and fluorobenzene
This species is a derivative of benzene, with a single fluorine atom
attached. Its melting point is -44 °C, which is lower than that of
benzene, indicative of the remarkable effect of fluorination ...
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Why is the boiling point of heavy water higher than normal water?
In class, we learned that London forces become stronger as relative molecular mass increases. Not just in organic chemistry but in things like the halogens.
However, as I understand, the London forces ...
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1
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Why is the difference in boiling point so much greater between methanol and methane than it is between 1 decanol and decane?
So any data sheet will tell you;
...
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Arrange these compounds: CO2, CH3OH, RbF, CH3Br in order of increasing boiling points
Arrange these compounds: $\ce{CO2}$, $\ce{CH3OH}$, $\ce{RbF}$, $\ce{CH3Br}$ in order of increasing boiling points.
I think I should consider the forces between them, that is:
$\ce{CO2}$: dispersion ...
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Why does tetrachloromethane have a higher boiling point than trichloromethane?
London dispersion forces (LDF) are present in all molecules, whether polar or non-polar. Molecules also exhibiting dipole-dipole interactions (in addition to the LDF) must have stronger forces of ...
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Why Isodecane (B.P.: 327 *C) has a higher boiling point than decane (B.P.: 174.1 *C)?
Branched chain molecules have lower boiling point than straight chain molecules because branched chain molecules have a smaller surface area where they can be attracted by other molecules. Then, why ...
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Why does silicon tetrafluoride have a higher melting point than sulfur tetrafluoride?
So looking at the Wikipedia pages of sulfur tetrafluoride and silicon tetrafluoride, the melting points are −121 °C and −90 °C respectively, and so $\ce{SiF4}$ has the higher melting point. However, ...
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