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Questions tagged [boiling-point]

The boiling point of a substance is the temperature at which the vapor pressure of the liquid equals the environmental pressure surrounding the liquid

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Is 99% Isopropyl Alcohol sold in stores really 99%?

My understanding is that an azeotropic mixture of isopropanol and water is 91%. This makes sense as to why there are so many brands of rubbing alcohol sold at 91%. There are also some sold as 99%, ...
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2answers
43 views

Heat capacity and boiling point [on hold]

Two solutions are prepared using equal moles of water, at same temperature: One contains $n$ moles of $\ce{NaCl}$ and the other contains $n$ moles of $\ce{KNO3}$. Is the heat required to raise the ...
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0answers
23 views

How does this limit the value of boiling points as criteria for determining the purity of liquids? [on hold]

If ideal liquids x and y both have a boiling point of 110 C, what will be the boiling point of a mixture of x and y? How does this limit the value of boiling points as criteria for determining the ...
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3answers
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Why does increase in pressure cause a increase in boiling point [closed]

When we increase the atomospheric pressure pressure above the solution , the boiling point of a solution increases. Why does this happen?
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2answers
65 views

Boiling methanol in a microwave

Some protocols (metabolomics) use boiling methanol for metabolites extraction and cleaning glassware. Is it safe to boil methanol in a microwave?
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1answer
39 views

Is sodium hypochlorite 100% concentrate possible?

Popular bleaching brands like Clorox contain liquid sodium hypochlorite in small concentrations, ranging from 5-12.5% (is this a mass/volume, mass/mass, or volume/volume concentrate?). Is it possible ...
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1answer
36 views

Ionic factor of glucose? [closed]

I am trying to find the $K_\mathrm{b}$ for 50 g of glucose dissolved in 1 kg of ethanol, given the change in boiling point is $\pu{2.2 °C}$. The molality is therefore 0.278. But what is the ionic ...
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1answer
56 views

difference in boiling point of 2-iodopentane and 3-iodopentane

There is no difference in boiling point of 2-fluoropentance and 3-fluoropentane, so is chloro- and bromo-. But why is there a difference in the boiling point of 2-iodopentane and 3-iodopentane, up to ...
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0answers
48 views

Why is the boiling point of SbH3 higher than the boiling point of NH3? [duplicate]

Why is the boiling point (b.p.) of $\ce{SbH3}$ higher than the b.p. of $\ce{NH3}$ even though the melting point (m.p.) of $\ce{NH3}$ is higher? Hydrogen bonding occurs in $\ce{NH3}$, so shouldn't the ...
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1answer
111 views

Which solution has higher boiling point?

Between a 2%(w/v) aqueous solution of NaCl and RbCl, which will have a higher boiling point. Here there are two competing factors. First there's the fact that NaCl has a higher concentration. So it's ...
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2answers
60 views

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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1answer
41 views

Why does phosphine have a dipole moment and a higher boiling point than carbon tetrafluoride?

Phosphine, PH3, and carbon tetrafluoride, CF4, are small molecules of a similar size and the same mass of 88 au. CF4 has a dipole moment of 0, which is unsurprising given its tetrahedral shape. ...
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48 views

On what factors do melting and boiling points depend upon?

In my book there is a separate discussion given for trends in melting and boiling points in each chapter in inorganic chemistry (the chapters on the various groups like group 15, group 16, etc.) and ...
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1answer
165 views

Melting point vs Freezing point

Is it possible to have Melting point different that Freezing point I mean is there any element/molecule in the liquid status that freeze at point X Centigrade but when it become solid then you need a ...
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1answer
153 views

Are specific heat capacity and boiling point of a substance related or proportional to each other?

That is, if the substance has a high specific heat, will it also have a high boiling point? ( and vice versa)
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1answer
38 views

Boiling of a liquid [duplicate]

Consider water as an example. I m really confused when does boiling takes place. When it's vapour pressure equals atmospheric pressure or when it's saturation atmospheric pressure equals atmospheric ...
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0answers
43 views

Boiling point of water [closed]

I was doing an experiment on boiling-point of water and I was supposed to measure the temperature of the water when it boils, but I saw the there were droplets of water on the lid of the pot, and I ...
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1answer
38 views

Which chemical could be used to decrease water boiling point to a minimum possible level without heating it [closed]

I aim to decrease boiling point of water that will be used to generate steam. I wonder maybe there is an opportunity to add a substance that will help to decrease boiling point of water without ...
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1answer
120 views

PCl3 vs SCl2 boiling point

Why does sulfur dichloride have a lower boiling point than phosphorus trichloride? Is it to do with the higher number of electrons causing stronger id-id interactions in PCl3, or do we need to compare ...
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0answers
56 views

Reason for formation of bubbles at boiling point [duplicate]

As I understand it, boiling takes place when the saturated vapour pressure equals to the atmospheric pressure. But, why does the vapour pressure need to be equal to the atmospheric pressure for ...
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0answers
49 views

Molar entropy of vaporization

If a substance has a molar heat of vaporization of $\pu{3.05\times10^4J/mol}$ and a normal boiling temperature of $\pu{80.0^\circ C}$, what is the value of its molar entropy of vaporization $\Delta S_\...
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0answers
728 views

Explain the effect of intramolecular hydrogen bonding on solubilities in cold and hot water?

There is a statement given in my textbook (Cengage, Organic Chemistry (Part 1), page 4.33) which is as follows: (I edited the statement to make it simpler) One can account for the solubilities of ...
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1answer
112 views

Is it true that an evaporating molecule has the same kinetic energy as a molecule in a pot of boiling water?

A molecule on the surface of room-temperature water shoots off the surface of said water, or in other words, it "evaporates." It does so because it gained kinetic energy ...
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1answer
137 views

Does sodium ethoxide (sodium ethanolate) have a boiling point, or does it decompose?

According to Wikipedia, $\ce{C2H5ONa}$ melts at 260°C, but no boiling point is given. What will happen if $\ce{C2H5ONa}$ is heated further?
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2answers
46 views

Find the boiling point of a compound given a pressure

I need to find the boiling point (in degrees centigrade) of ethanol on a day when the atmospheric pressure is $780\text{ torr}$. I know that the molar mass of ethanol is $46.07\text{ g/mol}$ but I ...
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0answers
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what is the purpose of steam in 'steam distillation' of aniline?

According to me,steam helps in increase in the vapour pressure so as to reduce the boiling point of the mixture. In my book,it is given that steam is used to reduce the vapour pressure of the liquid. ...
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1answer
82 views

Does the van der Waals force not affect the alkali metal 's trend of decreasing melting points down the table? [duplicate]

Melting and boiling points increase further down the halogen group, but they decrease further down the alkali metal group. I know that the former's trend has to do with the van der Waals force, but I ...
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2answers
69 views

Does boiling milk really make the nutrients in it less useful to the body when ingesting it?

Does “denaturing” nutrients in milk by boiling it make them less useful, or actually more useful, as they undergo “denaturation” anyway during digestion? I've read online that boiling milk "denatures"...
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1answer
1k views

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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0answers
500 views

Why is the boiling point of para hydroxybenzoic acid lower than that of ortho hydroxybenzoic acid?

As per the literature at 760mm of mercury, p-hydroxy benzoic acid has lower boiling point ($\pu{336^\circ C}$ - ChemSpider) than o-hydroxy benzoic acid ($\pu{372^\circ C}$ - ChemSpider). What is the ...
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0answers
30 views

How does vacuum affect the boiling point of a liquid? [duplicate]

I was searching about the boiling point of a liquid. How does vacuum affect the boiling point of a liquid?
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1answer
377 views

Why is the difference between the melting point and boiling point large for some compounds, and small for others? [duplicate]

I was looking at a list of melting and boiling points of various compounds and I realised some had very large differences while some have very less differences between their melting and boiling points....
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For a given period, why is the boiling point of the halogen greater than that of the noble gas?

The boiling point of bromine, a halogen, is $\pu{58.8^\circ C}$, while the boiling point of krypton, the noble gas in the same period as bromine, is $\pu{-153.4 ^\circ C}$. I thought that the larger ...
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1answer
192 views

How can HCl be liquid if it has a boiling point at -85°C?

Shouldn't it at least be boiling? When water reaches its boiling point it makes bubbles, but that doesn't happen with HCl, why? Did I misunderstand some basic chemistry?
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0answers
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Change of properties from Propanol to Butanol [duplicate]

This might be a silly question, but I couldn't find a nice answer. Reading the properties of short alcohols I found some data and made this table: PS: I apologize for the footnotes. S= solubility. ...
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1answer
325 views

Is there a relationship between boiling point and van der Waals constants [closed]

Is there a relation of the boiling point of a gas with its van der Waals constants, $a$ & $b$? I know if constant $a$ is greater, then the boiling point will also be greater, because of more ...
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1answer
285 views

Why does acetonitrile have a larger dipole moment and boiling point than acetaldehyde?

Experimentally, acetonitrile has a larger dipole moment than acetaldehyde, but I've never understood why. I always thought that the charge separation between carbon/oxygen is larger than that of ...
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2answers
2k views

Why do alkanes have higher boiling point than their ether counterparts?

Based on my understanding of inter-molecular forces, I expect dipole-dipole interactions to be significantly stronger than van der Waal's interactions. Hence, I expect ethers (which obviously have ...
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0answers
43 views

Fluorocarbon wrong density specifications

I found this data table and in density row, the information seems wrong to me. The problem is that some of these fluorocarbons are in gas form while others are in liquid form at the temperature that ...
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1answer
2k views

Boiling point trend in group 13

My Theory: Since atomic mass increases down the group, the van der Waal's forces should also operate to a greater extent, thereby making it difficult to change the phase of the substance. Hence, ...
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1answer
1k views

How to compare the boiling point of water, ammonia and hydrogen fluoride?

According to the values of boiling points that I found on internet the order is as follows: $\ce{H2O}$ > $\ce{HF}$ > $\ce{NH3}$ I was expecting $\ce{HF}$ to have highest boiling point because F ...
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1answer
799 views

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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2answers
860 views

Enrichment of D2O

The Wikipedia page for deuterium oxide (heavy water) says that its boiling point is 374.5 K and the one for ordinary water is 373.13 K. Is there a way of distillation which we can use to enrich ...
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3answers
1k views

Lowering the boiling point of wax

Wax comes in all kinds (paraffin, bee wax, palm oil wax, gel wax, ...) but since it's usually a mixture of different carbonated chains, its physical properties vary a lot from one manufacturer to ...
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1answer
65 views

When boiling a liquid, how vapour pressure and ambient pressure get equal? [duplicate]

When boiling a liquid, how vapour pressure and ambient pressure get equal? As vapour pressure will increase, it will lead to increase in ambient pressure also. let, Initially there would be some ...
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1answer
1k views

General organic chemistry [closed]

What is the correct order of boiling points of the following compounds ? 1) butanol 2)butanal 3)butanoic acid
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1answer
511 views

Boiling point of alkynes from n = 2 to 10

From a video on organic chemistry, I found this table that shows the boiling point temperatures of alkynes $\ce{C_{n}H_{2n-2}}$ with $\,n=2...10$. $$\begin{array}{|c|c|c|c|} \hline n & t_\mathrm{...
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1answer
648 views

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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0answers
17 views

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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0answers
226 views

Do mixtures have a boiling point?

Let's assume a mixture which can be heated without decomposing. This site explains that while pure substances have a sharply defined melting point and boiling point, mixtures tend to have a melting ...