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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Why do the melting points of Group 15 elements increase upto Arsenic but then decrease upto Bismuth?

The boiling points of group 15 elements increase on going down the group (or, as size increases) but the same is not true for the melting points. The melting points increase from $\ce{N}$ to $\ce{As}$ ...
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Throwing water into lava

While discussing magma in class with my students, I showed a video of a man throwing water onto molten, running lava. A large flame ensued. I realize that the water is being converted into steam and ...
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Hydrogen bonding in alcohols vs amines

Consider an alcohol and an amine compound with roughly the same molar mass. If I understand correctly, the boiling point for the alcohol is greater for two reasons: The $\ce{O-H}$ bond is more polar ...
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Does a freezing point of a substance always increase as its boiling point increases?

I am studying for an introductory to physical sciences test and came upon a chart describing substances found in petroleum and the distillation process. Each freezing point increases as each boiling ...
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Boil to dry 50 liters water

I would like to find out how long it would take to completely turn 50 litres of water to steam. Let's assume power of 2500 W and the water is already at boil. I am not very scientific so please ...
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Elevated boiling points in alkanes with even number of carbons [duplicate]

Why do alkanes with even number of carbon atoms have greater boiling points than those with odd number of carbon atoms?
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Is there a liquid that looks like water but boils at a low temperature? [closed]

I just watched a movie where someone put their hand into boiling water. Disregarding how this was actually done, I wondered whether there was a liquid which could be used for an illusion of someone "...
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Does fumaric acid form stronger hydrogen bonds than maleic acid?

My book claims: Fumaric acid can form intermolecular hydrogen bonds (strong) while maleic acid forms intramolecular hydrogen bonds (weak), hence fumaric acid has higher boiling point than maleic ...
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Why is CH4 a gas at room temperature but CH3Cl a liquid?

I cannot figure out a question on my review sheet. The full question is: Methane ($\ce{CH4}$) is a gas at room temperature but chloroform ($\ce{CH3Cl}$) is a liquid. Explain why changing just one $\...
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Boiling point of vodka

What is the boiling point of vodka? I have found the boiling point of ethanol, ~173 (degrees) F. However, I am unable to find the boiling point of vodka. I found some information on it, but I do not ...
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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 is latent heat of vaporization not exactly proportional to boiling point?

Latent heat of vaporization and boiling point are both chemical properties related to the bond strength of the molecule. In general, the higher the boiling point is, the higher the heat of ...
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Why does dimethyl sulfoxide have higher boiling point than acetone?

They have very similar structure except for a central atom, but the difference in boiling points is very large $(\pu{186 ^\circ C}$ for DMSO and $\pu{56 ^\circ C}$ for acetone). How is central atom ...
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Does the boiling point of an aqueous solution depend on what the solute is?

Consider a situation where we have two aqueous solutions which have the same concentration (e.g. 1 M), but the solute is different. For example, one is a solution of glucose, and the other is a ...
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Does supersaturated caffeine polymerize?

I tried preparing a supersaturated solution of caffeine by mixing anhydrous caffeine powder with water in a thin Turkish tea glass and heating it up over a candle (desperate times...). This worked ...
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Smelly matters in urine - do they have lower or higher boiling point than water?

I don't know what exactly are the compounds that causes urine to be smelly, but does it (or do they) have higher or lower boiling points than water? If I have both liquid and exposed them to open air, ...
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The Boiling or Evaporation of Diethyl Ether

When we heat water, we see bubbles appear as the boiling point approaches. The water then "boils" vigorously as it is converted from the liquid phase to a gas. I realised recently that during an ...
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Will the water at the bottom of the tube boil at the same temperature as the water at the top of the tube?

Consider a long, vertical tube of water, as shown below: Where $P_\mathrm{atm}$ is the atmospheric pressure and $P_\mathrm{bottom}$ is the pressure at the bottom of the tube. The tube is long ...
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Calculate Ethanol content after heating for N minutes

Does there exist a formula I can use to calculate alcohol content of a solution after heating it for some time? I have the following use-case: I am making a pecan pie. I have a thick sugary solution. ...
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Boiling point of Coca-Cola

Inspired in part by the question boiling point of vodka - given that the exact ingredients of Coca-Cola are kept secret, based on what is known, what would a viable prediction of the boiling point of ...
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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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Any examples of liquids volatile at room temp but non-flammable?

I'm thinking of something similar to the liquid used in the classic dipping birds. Temperature differential in two "bulbs" at each end of a tube should cause vapor to expand and push liquid to the top,...
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At what temperature (in kelvin) are most of the elements on the periodic table liquids?

This question is out of pure curiosity. At what temperature are a majority of the elements on the periodic table in a liquid state/phase of matter? For the purpose of this question, assume the ...
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Boiling point of a liquid increasing with temperature?

In my textbook, a statement is given, as follows: Boiling point of a liquid increases with increase in temperature However, I was wondering, isn't this wrong? The boiling point of a liquid always ...
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Boiling-point elevation paradox

This is the boiling-point elevation equation: $$ \Delta\mathrm{T}_{b}=ib\mathrm{K}_{eb}. $$ If we do the limit of the above, for $b\rightarrow\infty$ we find that the boiling-point elevation is ...
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Boiling point comparison between cyclohexane derivatives

I am trying to order these according to boiling point. I think that B is the highest because it has hydrogen bonding. I am not sure how to differentiate A and C though. They both have about the same ...
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At what temperature will proteins and fats boil in a vacuum?

A question was asked on another stackexchange site: This is not nice perspective, but eventually it will happen. An astronaut falls out of spaceship because of damage caused by collision with other ...
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Why is the boiling point of sugarcane juice lower than the boiling point of water?

As the boiling point is a colligative property, one would expect that the boiling point of sugarcane juice should be higher than pure water because Sugarcane juice contains water (75–85%), non-...
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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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Can I make a container of (kind of) perpetually boiling water?

It's a common school experiment to make water boil at room temperature by putting it in a container and reducing pressure. I am wondering if it is possible to make a sealed sphere containing water ...
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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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Boiling/melting points of cyclohexane and cycloheptane

I’m looking at a chart in my book, and while cycloheptane has a higher boiling point than cyclohexane like I’d expect, cycloheptane has a melting point of −12 °C, while cyclohexane has a melting point ...
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Is using melting/boiling point good to measure volatility?

I wanted to figure out a way to compare volatility in organic compounds, so I read on many forums on the differing ways to measure volatility, which included enthalpy of vaporization and melting/...
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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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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 ...
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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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Molecular weight determination from freezing point depression

Which is the better solvent for molar mass determinations by freezing point depression, benzene or cyclohexane? Which is the better method for molar mass determination, freezing point depression or ...
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Why does tomato soup “explode” when boiled?

When you boil tomato soup it very easily "explodes" when reaching the boiling point. Why is that? A related question has been answered here before: Why do some solutions eventually stop boiling and ...
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1answer
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What is the temperature needed for a reflux using a mix of solvents as the reaction medium? [closed]

I had a quick query regarding the setup of a reaction. The procedure that I am working from states that I need to put my reaction mixture under reflux for 3 hours. The solvents used are diethyl ether (...
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The boiling points of Alkali metal group

As I know, the melting points of Alkali metals decrease down to the group due to decreasing of the energy of the metallic bond. But according to my understanding, after it has become to liquid the ...
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Why is the boiling point of alkyl iodide is more than alkyl fluoride?

As far as I know, more the polar character of the organic compound, more will be the energy required to break the bond and thus more boiling temperature. Here in this case, $\ce{R-F}$ is more polar in ...
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Heating of mixture of gases with one gas barely above its boiling point

What happens when mixture of two gases is heated in a closed container? If one gas expands faster than the other and increases pressure of the container enough so that the boiling point of the other ...
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Which factors best account for the increase in boiling point?

The boiling points of $\ce{CH3COCH3}$, $\ce{CH3COC2H5}$, and $\ce{CH3COC3H7}$ are $56˚C$, $80 ˚C$, and $102 ˚C$, respectively. What factor(s) best account(s) for this? I believe london dispersion ...
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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 are branched isomers less polarisable?

This fact was given as an explanation as to why branched isomers of a compound have lower boiling points. How are branched isomers less polarisable and how does this relate to London dispersion ...
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How can a substance have a higher boiling point but lower melting point than another substance?

Looking at 1,3-Butadiene and Isoprene, I'm wondering: why does Isoprene have a higher boiling point, but a lower melting point than 1,3-Butadiene? I'm thinking this might be because the Methyl group ...
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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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Boiling and Melting point of Lithium (or any other element that does not occure in free state)

The melting and boiling point of Lithium as compared to other members of the Alkali group metals is high. But, Lithium does not occur in the free state. So, what does it mean that it has high ...
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Which among phenol and 1,2-dihydroxybenzene has the higher boiling point?

My attempt Based on symmetry: I think that looking for symmetry phenol has a higher boiling point than 1,2-dihydroxybenzene because the two -OH groups projecting out from the benzene ring of 1,2-...