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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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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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.
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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 ...
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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 ...
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Comparing the strength of metallic bonds

Why is the boiling point of iron higher than magnesium?
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Variation of Boiling point with pressure from Clausius-Clapeyron equation

For a first-order phase transition such as water to steam , we write Clausius-Clapeyron equation as: $\frac{dP}{dT}= \frac{L}{T \Delta V}$ Now what I infer from this equation is that if the phase-...
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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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Boilling colloidal silver?

I have some colloidal silver that i bought from a shop. It is 18ppm, however, I need a higher PPM and I can't seem to buy it anywhere where I live. If I boil this colloidal silver, would it make the ...
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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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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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570 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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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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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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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}{...
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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, ...
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820 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 ...
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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 ...
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Vapor pressure, volume and boling point

The saturated vapor pressure is designated as the gas pressure in a closed container when the evaporation process has reached an equilibrium (when there are as many molecules returning to the liquid ...
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What is the temperature at which lava evaporates?

According to this article -> http://ntrs.nasa.gov/search.jsp?R=19660041998 Lava evaporates under natural conditions, but apparently, only a little bit. I'd like to know the temperature at which ...
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What is the correct order of boiling points for group 15 hydrogen compounds? [duplicate]

What is the order of boiling points of the following $\ce{NH3}$, $\ce{PH3}$, $\ce{AsH3}$, $\ce{SbH3}$ and $\ce{BiH3}$? What I thought was, that as $\ce{H2O}$ has a higher boiling point compared to ...
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The effect of pressure on boiling point?

My textbook states the following: Qualitatively, I understand why the boiling point of a substance increases when the pressure is increased. However, I learned that if the pressure is increased when ...
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How do foundries prevent zinc from boiling away when alloyed with Aluminum?

How do foundries prevent lower boiling point metals such as zinc from boiling away when alloyed in a furnace with higher boiling point metals such as aluminum?
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What happens with the boiling point of a liquid in a vacuum [closed]

This may be a silly question, but when I was reading my chemistry textbook, there was this following statement: "A liquid boils when its vapor pressure equals the external pressure acting on the ...
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Comparison of boiling points

I was comparing boiling points of $\ce{CHCl_3}$ and $\ce{CH_3Cl}$. According to me B.P. of $\ce{CHCl_3}$ should be higher due to it's higher molecular mass than $\ce{CH_3Cl}$, but the answer is ...
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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} ...
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843 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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Melting and boiling point comparison

Graphite, silica and diamond are covalent compounds and still they have high melting and boiling points. Why?
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Is this the right conclusion for a thought experiment?

In this thought experiment, let’s consider the surrounding to be air that is composed of entirely water vapor (no other species like $\ce{O2}$ and $\ce{N2}$ are present). The surrounding is infinitely ...
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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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Microscopic and mechanical approach to boiling point [duplicate]

I am confused as to how I should visualize the boiling process throughout a liquid. From my understanding, the boiling point of a liquid is when its vapor pressure reaches atmospheric pressure. This ...
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9k 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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Compare the boiling points of isobutane and 1-butyne

Question: Compare between the boiling points of isobutane and 1-butyne The answer to this question is given as 1-butyne has higher boiling point than isobutane. My approach: I have been taught a few ...
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Latent heat of vaporization/evaporation

It's the amount of heat required for liquid ---> gas phase change of a substance at it's Boiling point. But my question is, does providing energy equivalent to latent heat of vaporization to a ...
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why does a pot of boiling water quiet down after it reaches boiling point but is still roiling?

I've noticed that when water boils, it makes a lot of noise. After the water reaches boiling point, even though the water is still ""rolling", the water quiets down. What is all the noise about and ...
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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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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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Boiling point and vapor pressure

Does a liquid having higher vapor pressure have a lower boiling point? I think so because I read in wikipedia that, "A substance with a high vapor pressure at normal temperatures is often referred to ...
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902 views

Calculating boiling point of a solution

What is the boiling point of an aqueous solution that has a vapor pressure of $23.0~\text{Torr}$ at $25~^\circ\text{C}$? $(P^\circ_{\ce{H2O}}=23.78~\text{Torr};~K_\mathrm b= 0.512~^\circ\mathrm{C\ kg/...
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Melting point of objects and food

What is the melting point of egg yolk? Well, generally, when we break an egg, the yolk is in liquid state. After we pour it on a pan, the egg starts to cook and it hardens. My question is, can an egg ...
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Which one has the highest boiling point?

10 g of substance below were dissolve in each 1 L water: $\ce{Na2SO4}$ $\ce{NaCl}$ Glucose $\ce{MgCl2}$ Which one has the highest boiling point? Glucose has London dispersion force. $\ce{Na2SO4},$ $\...
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At boiling point, is the total pressure twice the atmospheric pressure? [duplicate]

We know that one definition of boiling point is that it's the temperature at which the vapor pressure is same as the atmospheric pressure. Assuming a closed container, does that mean that at this ...
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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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When comparing boiling points of two ionic compounds, what bonding factors should you assess?

When comparing boiling points of two ionic compounds, should you look at their electronegativity difference, lattice energy, or strength from LDF forces (or all 3 factors)? For example, between LiCL ...
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How do I know how many molecules a solute will split into when it dissolves in a solvent?

I'm in high school and I'm learning about freezing point depression and boiling point elevation. I've been given this chemistry problem: Acetic acid has a boiling point elevation constant of 2.93 ...
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Why is the boiling point of rectified spirit lower than alcohol absolute?

The boiling point of rectified spirit is ($78.1~\mathrm{^\circ C}$) while that of absolute alcohol is ($78.3~\mathrm{^\circ C}$). I know its too small, but shouldn't the addition of impurities ...
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Boiling and Exploding Beaker?

A few days ago, I was creating a solution which involved boiling water. I had two 4L beakers on identical hot plates. After around 10 minutes, the first one boiled. Waiting another 30 minutes, the ...
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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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What is the vapor pressure of a liquid if it is not in a sealed container(i.e., a river or lake)? Is it just the atmospheric pressure? [closed]

From what I understand, the boiling point of a liquid is when its surrounding pressure is equal to its vapor pressure. The vapor pressure is the pressure of the gas form of the liquid in a container ...
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310 views

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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Can eggs boil indefinitely?

At breakfast someone asked if the eggs were boiling. While obviously they meant the water for the eggs, but it lead to a discussion regarding if you can make an egg boil without it coagulating or even ...