What is Boil: Definition and 59 Discussions

A boil, also called a furuncle, is a deep folliculitis, infection of the hair follicle. It is most commonly caused by infection by the bacterium Staphylococcus aureus, resulting in a painful swollen area on the skin caused by an accumulation of pus and dead tissue. Boils which are expanded are basically pus-filled nodules. Individual boils clustered together are called carbuncles.
Most human infections are caused by coagulase-positive S. aureus strains, notable for the bacteria's ability to produce coagulase, an enzyme that can clot blood. Almost any organ system can be infected by S. aureus.

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  1. P

    Vapor pressure -- How does water still boil at 100°C in an open pot?

    Vapor pressure is the pressure of the vapor when it is in equilibrium with its liquid. This only happens when the container where the liquid is present is closed. Indeed, when the container is open, this liquid-vapour equilibrium is never reached, because the partial pressure of the vapor (at a...
  2. K

    B Cheapest equipment to boil water at 60℃

    Water (any liquid) in a closed container boils when the vapor pressure of water (a property that depends on its temperature) equals the surrounding pressure. The vapor pressure of water at 60℃ is about ##1.99\times10^{4}## which is roughly 150 mm Hg.This principle is so simple, and yet, it is...
  3. Y

    Can someone tell me which formula to use here? (time to boil water)

    An amount of water at a temperature of 20 °C is passed through a water boiler in 1.5 min to brought to boiling point. The kettle is broken and does not jump off. The time between the moment when the water reaches boiling point and the moment when all the water is evaporated, is equal to: a) 7,5...
  4. J

    Adding xylitol to hot water lowers the boiling point and makes it boil

    This probably occurs with salt too but let's concentrate on xylitol: you heat water till it boils, put the hot water in a cup and add a tsp of xylitol. It boils again violently for a couple of seconds. The high school explanation is that the boiling point of the water is lowered. I'd like to...
  5. C

    At what wind speed will salt water "boil"?

    During hurricane Lenny in 1999, I was anchored on my sailboat in a protected cove in the Virgin Islands. The winds were about 60 mph with gusts to an estimated 80 mph where we were. I observed that during the gusts, the salt water would "boil", that is, totally evaporate the surface into a cloud...
  6. E

    How long will it take to boil 1 liter of water?

    Hi. I have been trying to solve the following problem:How long will it take to boil 1 liter of water from 20°C? The heat efficiency / η is 85% , voltage / U 230V and power / P 200W. The answer must be given in seconds. So, t1 = 20°C t2 = 100°C Δt = 80°C V = 1,0 liter → m = 1,0 kg...
  7. M

    What would happen to a blob of mercury in space?

    How long would it take for a blob of mercury (the size of a marble or so) to freeze in space? I'd emagine it would have to boil in some way first, and that would send pieces of it flying around, but the surface tension of mercury is much greater than that of water, or urine (as we'd seen...
  8. EEristavi

    I Liquid boiling and Evaporation

    In the normal conditions (sea level) water evaporates at 100 C. In thermodynamics, we say: the amount of energy Q, can raise temperature of the liquid by the formula Q1=cm(t2-t1); when the liquid reaches the boiling point (100 C), we write Q2=Lm. Q2 is entirely spent on changing liquid state...
  9. M

    Sizing a Solar Array To Boil Water

    Hello, I am having a hard time deciding the size of a solar array to boil water for a school project. Before putting any thought into the subject I simply thought that I would just take the wattage of the panels and add them up since they are added in both series or parallel and then select an...
  10. G

    Boil by increasing temperature or reducing pressure?

    Which one is cheaper to do if I have a reactor at 45 bar, 80C and wish to distill a substance before it enters another reactor at 15 bar, 150C?
  11. moenste

    Heating water in a kettle (time, boil out time, work done)

    Homework Statement A domestic kettle is marked 250 V, 2.3 kW and the manufacturer claims that it will heat a pint of water to boiling point in 94 s. (a) Test this claim by calculation and state any simplifying assumptions you make. (b) If the kettle is left switched on after it boils, how long...
  12. 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...
  13. 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...
  14. A

    Equation for time to boil water? Some T over t dropping....

    Hi, I am sorry I just forgot formula to calculate how long it will take to boiling water -> some lower temp. Thanks in advance.
  15. G

    Comparing the boil time for a copper and steel kettle

    Homework Statement Your friend prefers to use a glass kettle with a copper base. You notice that the water takes less time to boil when using this kettle compare to the stainless steel one. Explain the phenomenon behind this observation. Homework EquationsThe Attempt at a Solution 1. Heat is...
  16. Z

    Can a Steel Vessel Contain Liquid Hydrogen at 15,000 PSI and 25C?

    I've read a fews post about liquid hydrogen boil off, but could use a bit more clarification; insight on the following thought experiment would be really helpful: What happens if I take a 1 L steel vessel, put 1 L of liquid H2 into it, seal it off, and let it sit in a room at 25C? The density...
  17. 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...
  18. E

    Time for temperature of water to raise

    Homework Statement How long will it take to heat 40 gallons of water from 70°F to 120°F with a 20 kW immersion heater assuming no energy is lost the environment? Homework Equations It takes an electric tea kettle with 20°C water five minutes to reach boiling at 100°C. How long will it take for...
  19. T

    Why does water boil faster in high region than low region?

    Why does water boil faster in high region than low region?
  20. M

    Should not all substances boil in pure vacuum?

    It is well known that when the vapor pressure of a substance is bigger than the external pressure, it boils. In vacuum there are no particles and therefore no pressure, shouldn't therefore, even diamond as for example, boil in complete vacuum?
  21. N

    Calculating time taken to boil water

    Hi Need help please... my very limited knowledge of physics is very rusty lol...Im trying to work out the following: Basically if i have 50litres of water in a metal box how long will it take to boil off when heated to 800°C? And is there an equation for? Thanks very much in advance
  22. I

    [Help] battery power to boil water

    Hello everyone, I'm stuck at a basic physics challenge that I randomly thought on the drive home from work. The quick question is: how do i find out the amount of rechargeable batteries needed to boil water from room temp (20°C)? My research: A kettle uses a power cord connected to the...
  23. A

    Maximum Mass You Could Boil with 1000 J of Heat (Thermodynamics)

    Homework Statement What is the maximum mass of ethyl alcohol you could boil with 1000J of heat, starting from 18∘C?Homework Equations Q=mcΔT c ethyl alcohol = 2400 J/(kg*K) T boil ethyl alcohol = 78 C = 351 K T starting = 18 C = 291 K The Attempt at a Solution m=Q/(c*ΔT) m= (2400 J)/[(2400...
  24. T

    Is water 'supposed' to boil at a lower temperature?

    A biology teacher once said to his class something to the effect of water posessing qualities that it should not. I don't remember what reasons he gave but my notes say that water 'should' exist as a gas at -90 degrees Celsius at 1 bar. Do any of you know why this is?
  25. P

    Ammonia forced to boil because H2 is at 200psi ?

    Comes now the web page http://www.dr-fix-it.com/absorption.html which says that the ammonia-based absorption-cycle refrigerators ==do== operate only because droplets of liquid ammonia dripping into the ambient of the evaporator (= 200psi of pure hydrogen gas) can only continue to...
  26. W

    If the air is 212 degrees F will water boil?

    I've been trying to figure this our for a while now. My science teacher asked this question and he wants an answer by tomorrow but I have no idea. Can anyone help with this?
  27. S

    Boiling Points of Substances: Effects of Pressure and Temperature

    If no, which ones do not? If yes, is there a theoretical proof that a counterexample is impossible? Most substances have a fluid phase which is a single phase at pressures above critical point pressure - but two separate phases at lower pressures. The solid sublimates into a gas at lower...
  28. A

    Does stirring water help bring it to boil faster?

    Is it faster to leave the pot alone until it boils or to stir it every few minutes to increase convection? This is for a very large pot of over 50 litres using a 50 000 BTU commercial gaz burner at full power.
  29. hxtasy

    Whats more economical, filling pot with hot water, or cold, to boil water?

    I've always wished i could figure out how to calculate this. But don't know where to start. scenario: you have to boil a liter of water. if you fill it with cold water from your faucet, it will bill in X amount of time. if you fill the water with hot water from the faucet, it will boil...
  30. S

    How can I quantify/qualify liquid helium boil off rates based on dewar/cryostat size?

    I've been looking at various papers which describe the mechanisms and provide calculations describing heat flow into helium. I'm trying to minimize helium loss and am in the market for a new dewar flask/cryostat. I plan on asking the supply companies directly what the proper dimensions are to...
  31. S

    Steam required to boil a substance?

    Hi there, I am working on a process in which I have to melt 100 kg/h of plastic. The best way we thought of doing this was to use a boiler (steam generator) to produce sufficient heat to boil the plastics in time. I am currently trying to choose the right boiler for the system. Yet, I do not...
  32. T

    Depth of Water and Energy Required to Boil

    I have been out of college for more than 20 years and my basic physics knowledge has become quite rusty. Someone made a statement today related to making maple syrup. They stated the energy required to boil a pan of sap 2' wide x 3' long x 6" deep was the same as the energy required to boil 1"...
  33. K

    How big will the sun get when the seas begin to boil?

    First of all, I apologize if this is not the right place - it's my first post (although I've lurked for a while), so... er. Doomsday question. I'd like to know how big the sun will get - visually (but please without °, I am not educated enough to understand those) - at the end of its life...
  34. S

    Can Blood Literally Boil Inside the Human Body?

    Let's say that somehow your blood could literally boil. First of all, is that even possible? Second, how? What circumstances would you have to be in for your blood to boil? Also, in a kind of related question, if your blood did boil, would it cause you to swell and/or explode?
  35. M

    Thermodynamics, calculating the time it will take water to boil away

    Homework Statement Ok, so my book has the following problem: A kettle can heat 20°C water to 100°C in 5 minutes. How long will it take to completely boil it away assuming the same rate of heat addition. Homework Equations I think Q=mcΔT is relevant but beyond that I am struggling...
  36. M

    Help with understanding how to figure out the amount of heat to boil away water.

    [b]1. The problem statement, all variables and given/know 2300 grams of water is heated. If this water starts at a temperature of 17 degrees Celsius, what amount of heat is needed to boil away all of this water? Note that the specific heat of water is 1 calorie per gram per degree Celsius...
  37. T

    Why is it faster to boil water with the lid on

    I always though water boiled faster with the heat on simply because the lid retained heat. However, I was thinking about the enthalpy of vaporization. Could it be that there there is some sort of limit on how much water vapor air can hold, and beyond this it takes more and more heat to put...
  38. N

    How Much Energy Does It Take to Boil 3 Liters of Water?

    1. Problem, data and attempt at a solution How much energy is required to boil off 3 litres of water from 20*C? This is not really homework, but I still thought this would be the best place to post: To get something to compare to in terms of energy (joule/watt), I would like to know...
  39. I

    Time it takes for water to boil

    Homework Statement a 1200 watt heater is used for raising the temperature of 1 liter of water to boiling point. how long will itake for the water to boil of the initial temperature of the water is 20 degrees celsius? ( 1 cal = 4.19 joules) Homework Equations Q = mass * specific heat...
  40. B

    If The Sun Turned Completely To Water, Would It Freeze Or Boil?

    Lets say all the helium in the sun fused to make oxygen, if that and the hydrogen combined to make water, even though it doesn't work out perfectly, let's say it did, and the sun turned completely to water, would it freeze because of temperature cause it to freeze, or the pressure cause it to boil?
  41. B

    Can a Confined Liquid Boil? Understanding the Role of External Pressure

    I would have thought no, but my textbook appears to imply that the liquid being boiled in a confined space doesn't at its normal boiling temperature but does boil at a higher temperature. The reason I don't think a confined liquid can boil is because the external pressure in a confined liquid...
  42. A

    Why does milk overflow when boiled but not water?

    hi dear frns! why milks boil n overflow although this phenomenon is not seen in case in water?
  43. O

    Brewing Perfect Wort: Asking Tom Dible How Long to Boil

    Hello. I am not quite sure this is the correct place for this question so I will apologize now if it isn't. As a home brewer I mash the malt with hot water and collect the runoff (called wort) which contains the sugars needed for fermentation. Most recipes call for a boil length of either 60...
  44. O

    Brewing Success: Calculate Boil Length for Specific Gravity

    Hello. I am not quite sure this is the correct place for this question so I will apologize now if it isn't. As a home brewer I mash the malt with hot water and collect the runoff (called wort) which contains the sugars needed for fermentation. Most recipes call for a boil length of either 60...
  45. O

    Brewing Wort: Calculating Boil Length for Desired Gravity

    Hello. I am not quite sure this is the correct place for this question so I will apologize now if it isn't. As a home brewer I mash the malt with hot water and collect the runoff (called wort) which contains the sugars needed for fermentation. Most recipes call for a boil length of either 60...
  46. Y

    Why does water boil faster in a kettle then on the stove?

    This is probably a silly question, but it got me thinking. Why does water boil faster in an electric kettle then in a pot on a stove. Is it because a kettle can generate more heat energy? Anyone have any thoughts?
  47. L

    Why do noodles make the soup boil?

    When the soup is heated close to the boiling point and one puts noodles inside, it boils over (even if it is put away from the fire). Does anyone know why?
  48. P

    How Long to Boil a Larger Kettle of Water?

    My friend asks me this question, I have not worked it out. I hope it is suitable to maths box . The time to boil a small kettle of water using a electric coil is A minutes. Q: How many minutes needed to boil a big kettle (two times the mass of water compared to the small kettle), if using...
  49. M

    Boil Water At Low Temparatures

    I'm describing a little experiment that i conducted. Water or any liquid boils when its vapor pressure is greater than the pressure of the air above it.You can demonstrate this easily by using a disposable syringe. Suck water in the syringe so that it is about a quarter filled.(do it underwater...