What is Boiling: Definition and 319 Discussions

Boiling is the rapid vaporization of a liquid, which occurs when a liquid is heated to its boiling point, the temperature at which the vapour pressure of the liquid is equal to the pressure exerted on the liquid by the surrounding atmosphere. At sea level the boiling
point of water is 100 °C or 212 °F but at higher altitudes it drops to correspond with decreasing atmospheric pressures.
Boiling water is used as a method of making it potable by killing microbes and viruses that may be present. The sensitivity of different micro-organisms to heat varies. But if water is held at 100 °C (212 °F) for one minute, most micro-organisms and viruses are inactivated. Ten minutes at a temperature of 70 °C (158 °F) is also sufficient for most bacteria.
Boiling water is also used in several cooking methods including boiling, steaming and poaching.

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  1. D

    Melting point and boiling point

    Why there is huge difference in M.P. and B.P. Of Oxygen (M.P. - 54K,B.P.- 90K) and sulphur (M.P. - 393 K, B.P. - 718 K)
  2. C

    Two thermophores boiling water

    Homework Statement We are given two identical thermophores. It is known that one of them can boil a liter of water in t = 600 s. How much time would it take to boil one liter of water if we used two of these thermophores, connected a) in a series circuit b) in a parallel circuit Voltage: 230 V...
  3. T

    Why the temperature remains constant at the boiling point?

    Why all liquids vaporize on boiling point instead of the temperature gradually increasing along with vapor pressure and more liquid atoms evaporating? Does it have anything to do with formation of vapor bubbles?
  4. E

    I Is there a boiling analog to sublimation?

    Liquid water sitting can evaporate without a problem, given that the vapor pressure surrounding it is less than the temperature dependent saturated vapor pressure. Similarly, an ice cube can also evaporate without becoming liquid under these same conditions. However, an extreme form of...
  5. S

    Problem with boiling water and raising piston

    Homework Statement Consider a cylindrical tank closed by a movable piston with mass ##m=3 kg##. The radius of the cyclinder is ##r=7.5 cm##. In the tank there is a mass ##m'=2 kg## o water at temperature just below ##100°C##. At the base of the cyclindrical tank there is an electrical heater...
  6. T

    Highest boiling point between organic compounds

    Homework Statement The following substances have approximately the same relative molecular mass. Which is likely to have the highest boiling point? Homework EquationsThe Attempt at a Solution I chose E as it has OH so therefore hydrogen bonding. Is this correct? Cheers!
  7. kumar1405

    About contol rods used in boiling water reactor

    why Cross shaped contol rods used in boiling water reactor? thanks in adavance for answer .
  8. Ravi Singh choudhary

    Which will boil faster: steel ball in container or just water?

    Homework Statement Case 1: Which will boiling faster the container having steel ball dipped in it or container having only water? Case 2: Which one will attain thermal equilibrium faster? Consider balls are just in middle of the container. every condition of each the cases have same volume...
  9. jmarkwalker

    Evaporating water using heat and reducing vapour pressure

    I want to reduce the amount of water present in the digestate coming out of my Anaerobic Digester. The traditional method would be to boil it until I've removed as much off as I want. However, this is expensive from an energy consumption point of view. There's a great video on Youtube showing a...
  10. Biker

    I Understanding Boiling Point Elevation: Real Gas Law and Its Impact on Molecules

    So was thinking a little bit about the ideal gas law. ##P V = n R T## And I read an article about the real gas law where they just edited few properties. ##(P + \frac{n^2 a}{v^2}) (V - nb) = n R T ## Where a and b are constant determined experimentally. So going back to our original point, Why...
  11. PenguinCo

    Boiling water w/ a car battery

    So... I am looking to basically convert electric energy to thermal, then mechanical energy. I am wondering how practical it would be to use a rechargeable car battery (12V, and 40Ah) to boil water into steam for a steam engine. It does not matter how long it would take, simply if it is...
  12. Y

    Temperature of boiling surface

    What determines the surface temperature inside a pot of boiling water, right over the heat source? Can it go much over boiling temp if the water's just gently boiling?
  13. S

    Which has the highest boiling point?

    Homework Statement Which one of these had the highest boiling point? A. 3-Pentanone B. 1-Butanol C. Butanal Homework EquationsThe Attempt at a Solution The answer should be 3-pentanone because 1- it's molecular weight is approx 76 compared to the other which has approx 64 2 - because of the...
  14. S

    Calculate boiling rate of water

    How would I calculate the rate that water would boil off? I've done a lot of looking into and found an equation but it doesn't seem quite right. What I found states that the KJ/h delivered to the water divided by the latent heat energy gives you the amount of water that will boil off. I tried...
  15. Biker

    How Does Vapor Pressure Cause Water to Boil?

    I have searched about this topic all over the internet and non of them seem to explain how vapor pressure is equal to atmospheric pressure. All I need is some forces diagrams and some explanations. How when we increase the vapor pressure it makes the liquid boil faster? Isnt the vapor pressure...
  16. A

    Why boiling occurs at fix temperature?

    Can anyone explain to me why does temperature of water remains constant while boiling in an open vessel or in general sense why phase transition is isothermal in nature?please give me answers from thermodynamic point of view also.
  17. C

    How can I recreate this pressure boiling experiment

    Hi all, I was just wondering how I could recreate this at home What parts do I need? Thanks, Harry
  18. S

    Does boiling water remove chloramine?

    I ask because this website ( http://homebrew.stackexchange.com/questions/3447/what-are-the-various-ways-to-remove-chlorine-chloramine-from-tap-water?newreg=3134d1ed281145938fa4eefe2235b231 ) says that it doesn't, but I checked the boiling point of chloramine (on wolframalpha.com), and it's lower...
  19. C

    How can water be boiled without using heat?

    Hey everyone, I found this video on Youtube of this guy boiling water by reducing the pressure: I'm not sure how the gauge he's looking at works but I think this is the vacuum instrument he's using: https://us.vwr.com/store/catalog/product.jsp?product_id=4789427 ^It says that it provides...
  20. T

    Which Compound Has Highest Boiling Point?

    Homework Statement Of the following compounds, which has the highest boiling point? (A) CH3—CH3(B) CH3—CH2OH(C) CH3—COOH(D) CH3—COH(E) H2S Homework Equations - The Attempt at a Solution Chose C because is more polar with the 2 oxygens, however, the answer has conflicting answer. It...
  21. E

    Can boiling water inside steel cube make it explode?

    Hello Lets say we have a steel cube, then fill it with water and close all the gaps very strong with welding. If we leave the cube on a stove for a lot of time, is the produced steam of the boiling water, enough to destroy and smash the steel cube?
  22. S

    Intermolecular forces and boiling point

    I've come to understand that intermolecular forces cause the boiling point of hydrochloric acid solutions below 20% to be higher than the boiling point of water. I also understand that dissolving hcl in water is an exothermic reaction. But, what about those intermolecular forces. I assume they...
  23. T

    How do solute particles increase boiling point?

    The question is: Which solution listed below is going to have the highest boiling point? A. 1.5 m NaCl B. 1.5 m AgCl C. 2.0 m C6H12O6 D. 2.0 m CaCl2 E. 1.0 m Al2(SO4)3 I chose D (which was right) because in a solution, the more solute particles there is the higher the boiling point (this is...
  24. E

    Organic chemistry boiling point

    Homework Statement State true or false: The boiling point of propanoic acid is less than that of n-butyl alcohol, an alcohol of comparable molecular weight. Homework EquationsThe Attempt at a Solution Is this just a question where you either know it or don't OR is there some argument based off...
  25. faiziqb12

    How does temperature affect distillation in a fractionating column?

    i have got a question with distillation . in distillation as we know the mixture is boiled and the mechanism then goes like substances with high boiling points condense at the bottom and substances with lower boiling points condense on the way to the top. i don't know why , but i am having...
  26. S

    Energy loss when boiling in an water experiment -- help please

    Homework Statement Hi, as a part of my lab report I have to conduct this experiment : Fill a pot with tap water and boil it, determine then how much of the energy that the kitchen surface produced, actually went to the water itself. Consider the water having an initial temperature of 10 °C. In...
  27. ScepticAmatuer

    Boiling point of water heated via microwave

    I took about 100 ml of distilled water, put a small, clean rock in it (to prevent "bumping" or explosion) and heated it repeatedly in a microwave oven on high for 45 seconds. After each heating I checked the temperature of the water with a digital temperature probe. I did this 7 or 8 times...
  28. L

    Determining boiling point from vapour pressure

    Homework Statement When benzene freezes at 5.5 C its density changes from 0.879 g cm-3 to 0.891 g cm-3. Its enthalpy of fusion is 10.59 kJ mol -1. Estimate freezing point of benzene at 1000 atm Homework Equations Solid liquid boundary: p=p*+ΔHfus/ΔV ln(T/T*) The Attempt at a Solution From the...
  29. feyn

    How can boiling water freeze faster than water at room temp?

    Hi guys n girls, I have a real conundrum today. There us a rumor that if you put 2 pots of water, that are absolutely identical except that in one the water is boiling hot in the other it is room temperature, the one with the boiling water freezes faster. How can that be ? Pure logic dictates...
  30. UMath1

    Boiling Point of Rubbing Alcohol Lab | In-Class Experiment

    In class, we did a lab to determine the boiling point of rubbing alcohol. We used a thiele tube filled with water and place a test tube attached to a thermometer w/rubber band in it. However, we never saw any signs of boiling. We conducted several trials, the temperature went all the way above...
  31. MarcozXD

    Should carbon boiling stones be used in O-chem reactions?

    I performed column cromatography on an oil, and used carbon boiling chips but got some weird IR. I used hexanes and acetone as solvents, I am trying to figure out some of the spikes, soo I am thinking that maybe the boiling stone being carbon could acted as activated carbon and absorbed some...
  32. V

    Forever boiling water in vacuum

    Hello my first post :) I was wondering if it could be possible to achieve forever boiling of water in room temperature in vacuum. I understand that as water evaporates pressure increase and when equilibrium is reached, water stops boiling. But could it be possible to do that vapor in vacuum...
  33. rogerk8

    Why is boiling water bubbling?

    This is probably one of the most stupid questions you'll ever get. But I was looking at my boiling potatoes the other day and tried really hard to understand why the water was bubbling. I did understand that closest to the plate the water is hotter due to the stove than higher up in the "can"...
  34. B

    Minimal film boiling temperature (Core reflooding)

    Hello Forumers and Physics-addicted Fellows! I'm an applied nuclear engineering scientist by profession and thermal physicist by education. well nowadays I'm really involved into the describing the processes in Light Water Reactor core during Emergency Core Cooling System in action. In details...
  35. VoteSaxon

    Van der Waals and boiling point

    Homework Statement The bulb of a constant volume gas thermometer is immersed in an ice/water/water vapour mixture at equilibrium and the recorded pressure is 0.400 atm. It is then immersed in a boiling liquid and the pressure is 0.844 atm. Sufficient gas is then removed from the bulb such that...
  36. A

    Boiling point and vapour pressure

    Hi all, I am facing difficulty in understanding the reason behind the fact that a liquid boils when the atmospheric pressure is equal to its vapour pressure. We know that at the vapour pressure, the air and the liquid remain in equilibrium, so there's no net evaporation or condensation. So...
  37. A

    Why do sugars have higher boiling points than water?

    I recently heard about an interesting chemistry experiment I have yet to try. It involves boiling soda and watching the water rise and the sugars remain at the bottom of the pot. The reason being is sugars have higher boiling points than water. Thus, the water boils first, heats up, and rises to...
  38. R

    Maintaining liquid level inside a vessel of boiling liquid

    What's a good way to maintain liquid level inside a vessel of liquid that's heated via a jacket & has a feed pipe. Feed pipe is approx. 1/2 inch dia & expected flow in is about 300 Litres / hr Would a ball cock work with all that boiling & bubbling happening around it? I prefer a purely...
  39. Hang11

    Modeling boiling in a closed container with a small hole

    I'm trying to build a mathematical model of something like Heron's Aeolipile: http://en.wikipedia.org/wiki/Aeolipile I'd like to know, based on a known heat flux, the pressure and temperature attained in the container. I assume as water boils, the control volume loses mass and energy, the...
  40. K

    Dew point more important than boiling point

    I was thinking, the critical point between the liquid and gas phases is the dew point, not the boiling point, right? Melting/freezing on the solid/liquid boundary is analogous to evaporation/condensation on the liquid/gas boundary. Boiling is something totally different, and is not possible in...
  41. P

    Will Boiling Water Create Humidity?

    Is this a way to "humidify" your house? Will boiling water create humidity?
  42. F

    Boiling Water Temp: Celsius vs. Fahrenheit

    Homework Statement A Celsius and a Fahrenheit thermometer are dipped in boiling water. The temperature of the water is brought down until the Fahrenheit thermometer reads 140°. So, the fall in temperature registered by Celsius scale is: 30 40 50 80 Homework Equations F=(C*(9/5))+32...
  43. A

    Mysterious boiling phenomenon during experiment

    I am a student in my third year of engineering (materials science) and I was performing a lab experiment in which I was asked to calculate the heat capacity of metals using thermodynamic relationships. The experiment was done by placing a metal sample into a foam container filled with liquid...
  44. A

    Mysterious boiling phenomenon during experiment

    Greetings, I am a student in my third year of engineering (materials science) and I was performing a lab experiment in which I was asked to calculate the heat capacity of metals using thermodynamic relationships. The experiment was done by placing a metal sample into a foam container filled...
  45. L

    100% concentration of sulfuric acid by boiling isn't possible,why?

    why can't we get 100% concentration of sulphuric acid by boiling it?
  46. D

    Why Did It Take 15 Minutes for My Water to Boil?

    Hi, I noticed an interesting phenomenon when I was boiling the spaghetti yesterday. Please refer to the attachments. I poured about 200 mL of water into the pot and waited until it boiled.However,you know,it would only take you about 3 - 4 minutes to bring this amount of water into boil from...
  47. H

    Explaining Pressure: Boiling & Melting Point Changes

    So at increased pressure (increased atmospheric), the boiling point of water Increases because the atmospheric pressure goes up. But at increased pressures, the melting point of a substance decreases! The explanation i'v seen is that it is due to le chatlier's principle. Ice is less dense...
  48. M

    Boiling point Atmospheric/hydrostatic pressure

    So I understand that you get boiling when the vapor pressure equals atmospheric pressure so that the vapor within the medium can overcome the atmospheric pressure pressing on the surface of the liquid, but how do the bubbles overcome the hydrostatic pressure from the water above the bubble. If...
  49. F

    Heat Losses while boiling a pot of water

    Hi all, I'm a homebrewer and I'm trying to find the boil off rate in gal/hour when using an electric heating element in my kettle. If I'm using a 5500Watt heating element at 100%, I'm inputting about 312 BTU/min...Using this site and the table for the losses due to evaporation and radiation...
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