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

Filter by
Sorted by
Tagged with
2
votes
1answer
1k views

Effect of inductive effect on boiling point,melting point and dipole movement

In my book the following was written:- Inductive effect is a permanent effect operating in the ground state of the organic molecules and hence is responsible for higher melting point, boiling point ...
2
votes
2answers
409 views

How to determine the composition for a sucrose/ zinc nitrate solution from its freezing point?

A $4~\mathrm{g}$ mixture of sucrose ($\ce{C12H22O11}$) and zinc nitrate ($\ce{Zn(NO3)2}$) is dissolved in $150~\mathrm{g}$ of water. If the resulting solution freezes at $-0.768~^\circ\mathrm{C}$, ...
2
votes
1answer
348 views

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 ...
2
votes
2answers
5k views

How to determine the boiling point of substances? [closed]

Which of the substances has the lowest boiling point? a) $\ce{H2O}$ b) $\ce{H2S}$ c) $\ce{H2Se}$ d) $\ce{H2Te}$ I've been searching for any formula or rule to determine this, but I read that it ...
2
votes
1answer
881 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 ...
2
votes
2answers
2k views

How does hydrogen bonding affect the boiling points of chemical compounds?

My main question is why is the boiling point of methanol so much different from that of water? I understand that both compound are able to develop hydrogen bonding, and obviously water can develop ...
2
votes
1answer
179 views

Need help interpreting this data table (provided below)

I am confused about this data table. Can someone please explain how this person got a linear alkanes of differing molar masses? (I know some basics of organic chemistry, but I'm still learning.) Are ...
2
votes
1answer
374 views

Confusion about boiling point and vapor pressure [duplicate]

It is said that a liquid boils when its vapor pressure equals to the external pressure of its environment (e.g. atmospheric pressure). That’s because the bubbles of water vapor that form will be ...
2
votes
1answer
172 views

How can I calculate the boiling temperature of a pure substance as a function of pressure?

I want to make an algorithm that will give me the boiling temperature of a substance as a function of pressure, the critical temperature of a substance, and the critical pressure of a substance. I ...
2
votes
0answers
50 views

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 ...
2
votes
0answers
1k 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 ...
2
votes
0answers
172 views

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 ...
2
votes
0answers
94 views

Boiling Point trend

Why does group 13 and 14 show reverse the trend of boiling point? In other groups, boiling point increases down the group but here it decreases.
2
votes
2answers
9k views

Why is the boiling point of a solution higher than that of a pure solvent? [duplicate]

Why is the boiling point of a solution higher than that of a pure solvent? I think when a non-volatile solid solute is added to a solvent, some of the liquid solvent molecules are replaced by solute ...
2
votes
0answers
605 views

Dissociation of H3PO4 and colligative properties

Which of the following solutions that have concentrations of $0.01\ \mathrm{M}$ show the highest elevation in boiling point and why? A) $\ce{NaCl}$ B) $\ce{CaCl2}$ C) $\ce{H3PO4 }$ D) $\ce{...
2
votes
0answers
513 views

Why does cooking oil lower the vapor pressure of water?

I added different amounts of oil to different containers with 50mL of water and weighted the containers. Then I heated the containers for 15 minutes in a water bath and weighted again. I noticed that ...
2
votes
0answers
2k views

Why there is an exception in melting and boiling point in p block?

Why is the boiling point and melting point of 15th group and 16th group has an exception? We know that as molecular mass increases boiling point and melting point also increase. So, down the group 15 ...
1
vote
1answer
332 views

What [if anything] is special about the boiling process of purifying water (excluding temperature)?

I know that water boils at $100~^{\circ}\rm C$. I also know that the standard way to purify water is to boil it for roughly a minute. What I'm curious about is, what properties of the boiling process ...
1
vote
1answer
14k views

Liquefying butane in a freezer

If place a can of pressurized liquid butane (such as a lighter refill canister) into a freezer to get it below its boiling point of $-1\ \mathrm{^\circ C}$, and then release it into a container kept ...
1
vote
1answer
60 views

Change in boiling and freezing point

I recently encountered a question while solving previous year question papers for JEE. This is a JEE 2005 question. The question demands to complete this statement: Equimolar solutions in the ...
1
vote
1answer
1k 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 ...
1
vote
1answer
5k views

What is the boiling point and density of LSD?

I have tried to do a lot of research and didn't succeed to find the boiling point and density of LSD. I would want to know this information. In addition, I can't use Clausius–Clapeyron equation ...
1
vote
1answer
39 views

Boiling point elevation and liquid solutions

$\pu{1 L}$ of an aqueous solution of urea having density $\pu{1.06 g mL-1}$ is found to have elevation in boiling point $\Delta T_\mathrm{b} = \pu{0.5 °C}.$ If the temperature of this solution is ...
1
vote
1answer
1k views

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 ...
1
vote
1answer
250 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?
1
vote
1answer
201 views

Boiling points of v. similar organic molecules

Given the similarity in formula between pentane ($\small\ce{CH3(CH2)3CH3}$, b.p. 36.2 °C) and neopentane ($\small\ce{C(CH3)4}$, b.p. 9.5 °C), why are their boiling points so different?
1
vote
1answer
125 views

Elevation in boiling point of water [closed]

$\pu{1060 g}$ of urea aqueous solution is subjected to heating. It starts boiling at $\pu{100.53 °C}.$ It is heated up to $\pu{102.12 °C}.$ Find amount of water vapourised in grams. (Pure water ...
1
vote
2answers
5k views

how to determine the volatility of an organic compound using the physical properties of organic molecules

How do you tell if a compound has a high volatility? Also can the boiling point of a compound be taken into consideration when determining if a compound has a high volatility?
1
vote
1answer
4k views

Is it correct to say that SOME iodine undergoes sublimation at 1 ATM

The triple point of Iodine occurs at 0.12 atm and at standard temperature it is a solid on the phase diagram. I understand that therefore, when heating iodine at 1 atm, it (at least some of it) will ...
1
vote
1answer
830 views

Physical properties of phenols

Order of increasing boiling point is p-nitrophenol > m-nitrophenol > o-nitrophenol. The difference between bp of p- and o-nitrophenol is that one form intermolecular hydrogen bonding while other form ...
1
vote
1answer
294 views

How to separate benzyl alcohol and meta-cresol

Benzyl alcohol and meta-cresol boiling point's are not so different, the fractional distillation will be very difficult, what can i do for separate this two composites ?
1
vote
1answer
3k views

Why does butanoic acid have a higher boiling point than isobutyric acid?

Why does butanoic acid have a higher boiling point then isobutyric acid, when they have similar molar mass and molecular structure? Butanoic acid ($\ce{C4H8O2}$) has a molar mass of 88.11 g/mol, the ...
1
vote
1answer
601 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 ...
1
vote
1answer
342 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 ...
1
vote
1answer
155 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 ...
1
vote
1answer
2k 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 ...
1
vote
1answer
85 views

Colligative properties

I have some problems with these properties. 1) Lowering vapor pressure and boiling point. It happens because the solute molecules take space in the surface of the liquid so a lower number of the ...
1
vote
1answer
1k views

Why do ionic compounds have higher melting and boiling points despite having smaller radii?

Why do ionic compounds have higher melting and boiling points despite having smaller radii? I thought that the closer the two ions are, the larger the repulsive force, and therefore it should rather ...
1
vote
1answer
803 views

Comparing the strength of metallic bonds

Why is the boiling point of iron higher than magnesium?
1
vote
2answers
291 views

The relationship between energy and air pressure?

When boiling water at room temperature, what is the relationship energy has with the air pressure that is making the water boil cold instead of hot?
1
vote
0answers
122 views

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\ \...
1
vote
0answers
59 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 ...
1
vote
0answers
315 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_\...
1
vote
0answers
2k 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 ...
1
vote
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): ...
1
vote
0answers
231 views

Is my proof valid for the formula of elevation in boiling point? [closed]

Is my proof valid for the formula of elevation in boiling point? proof By Clausius clayperon equation, $$\ln(P)=-\frac{∆H_v}{RT}+c$$ Differentiating, $$\frac{dP}{...
1
vote
0answers
219 views

Can someone explain me the difference in boiling point of water when I add: KBr; CaCl2; AlCl3?

I have noticed (during an experiment) that the boiling point of the solutions created by H2O+KBr; H2O+CaCl2 and H2O+AlCl3 see their boiling point increase. During the experiment, I thought that, ...
1
vote
1answer
1k views

What are the boiling points of DMSO-water concentrations?

What are the boiling points of DMSO-water concentrations with respect to wt% DMSO? I have found extensive information on the freezing point change of wt% DMSO but nothing regarding boiling.
1
vote
2answers
555 views

Phase Diagrams and Equilibrium

In this link http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch14/phase.php It says (in the latter part ) that for all combinations of Pressure and Temperature along line BC the rate of ...
1
vote
0answers
227 views

What are the factors affecting Boiling Point in Ions?

I understand that for molecular substances, intermolecular forces such as van der Waals forces and hydrogen bonding are the major factors effecting the boiling point. However, I am not sure about ...