Why does it take longer to boil an egg at high altitude?

Answer 1

the atmosphere is thinner, less oxygen means the gas wouldn't burn as well and would take longer to heat the same amount of water than it would at sea level where the atmosphere is more dense

Answer 2

Soft Boiled Eggs High Altitude

Answer 3

Higher the altitude, lower the air pressure. Which means, the water boils at a temperature lower than the Sea Level. So, it takes an eternity for the egg to boil on the Alps.

Answer 4

As the height above sea level increases the boiling point of water decreases in direct proportion. It is no longer 100 degrees Celsius but a value below that.

At high altitudes, say near the summit of Everest it is impossible to brew ordinary tea in an open vessel as the water does not get hot enough.

However, an egg will COOK in its shell at high altitude but will take longer as the temperature is lower.

As a matter of interest distilled water would be produced more cheaply than at sea level as it boils at a lower temperature.

Another throw-a-away, at sea level alcohol has a boiling point of 70 degrees Celsius. How high would it have to be to boil off when you opened a bottle of whisky?

Answer 5

Cooking at High Altitudes

Why does water boil at a lower temperature at altitude?
Does food cook faster at a higher altitude?
Let's boil an egg...

The temperature of boiling water at sea level is 212 degrees Fahrenheit, or 100 degrees Celsius.

The atmosphere of air surrounding the earth creates a pressure against us and all objects on earth. This pressure at sea level is one atmosphere, (14.696 pounds per square inch (psi)), or if measured in mercury - 760mm (approx. 30 inches of mercury) in a column. It is the density of the atmosphere, or air, that causes the pressure.

As you increase altitude, the density of the air becomes thinner, and this thinner or less dense air then exerts LESS pressure. So, the higher the altitude the less dense the air and pressure decreases, until in space - no air, no density, no pressure.

Now, to boil water requires energy, this energy is in the form of heat and may have been produced by gas flame, electrical, solar, burning wood etc. As the water molecules are heated, the energy of the water molecules is increased, and they will vibrate or become more agitated, until finally the water molecules will break loose from the surrounding liquid water and rise up as steam. The water will also move quite violently due to the expanding dissolved gases that are contained in the water - hence the bubbles seen moving rapidly to the top of the boiling water.

So, you have introduced energy into the water to such a point that the bonding energy between the water molecules has exceeded the bonding threshold, and they have broken away and coalesced into steam.

What have been the influences on the water?
Pressure from the atmosphere at sea level - this has helped compress the water molecules together into a liquid.

The bonding energy between each water molecule.

As you increase altitude, the external pressure on the water is decreased, therefore it will take less energy to break the water molecules free from their bonded energy. If it takes less energy, then it will take less heat, as this is the energy we are introducing. If less heat is required, then less temperature is required, then the water will boil at a lower temperature

How about that egg we want to cook on top of a high mountain, say at 10,000 feet?
We now know that the water will boil at a lower temperature on top of the mountain at lets say, 185 degrees Fahrenheit. To hard-boil an egg at sea level takes say, five minutes at 212 degrees Fahrenheit.

Now, there is a very good law in chemistry that states "You cannot get something for nothing" (the left-hand value of an equation must equal the right-hand value). Time multiplied by temperature equals a hardboiled egg. That is to say, 212 times 5 equals a hardboiled egg.

If the temperature of the boiling water on the mountaintop is 185 degrees Fahrenheit, then the time taken to cook the egg will have to INCREASE to get our hardboiled egg. Our equation to equal a hardboiled egg cannot change. (185 times extended time equals hardboiled egg.) It is no different to cooking a piece of steak or cooking the potatoes. You can cook at a low temperature for a long time, or a high temperature for a short time.

It is time and temperature that does the cooking. It has nothing to do with whether the water is boiling. That is only a physical phenomenon that you can see. You have to measure for temperature and time, as these are the two factors that determine when the egg is hardboiled.

Answer 6

Water boils when its vapor pressure reaches atmospheric pressure. If you lower the atmospheric pressure by climbing up a mountain then your pot of water will boil but at a lower temperature. This boililng takes place at a constant temperature -you cannot heat the water past its boiling point.

These are the two factors missing from the above explanations:
1. definition of boiling ===> temp at which vapor pressure equals atmospheric; and,
2. the property that the water cannot be heated past its boiling point.

There are 2 techniques possible to help.
1. add salt to the water, the addition of a solute will elevate the boiling point; or,
2. use a pressure cooker -i.e. a sealed lid pot (with appropriate safety devices) to raise the pressure and therefore raise the boiling point.

Answer 7

Because the higher you are the less is the air pressure. The less the air pressure, the lower the boiling point of water. Thus, the higher you are, the longer it takes, because you're 'boiling' at a temperature which is less tan 100C/212F
PS: If you'll pardon the pun, aren't I a clever old ****! Oh for CHRISTS' SAKE YAHOO - What's wrong with that word that the capital letters of Can Only Cats Kill spell? I've used the word quite correctly but it's being starred-out because some pratt in America thinks it's a naughty word. Blood idiots. GROW UP - we're not all children in the UK!!!

Answer 8

because air pressure is less so the water boils at a lower temperature. because the temperature is lower it takes longer to boil. you could use this fact to make a perfect soft boiled egg as the 2 parts set at different temperatures so all you would need is to go high enough so that the water boiled at about 65 degrees centigrade (i cant remember the exact figure) and you would get a perfect soft boiled egg. hope this helps

Answer 9

At higher altitude due to low pressure the boiling point of water is lowered and it doesn't provide enough heat energy to cook or "boil" the egg .For the same reason pressure cookers are used.

Answer 10

A scientific fact...it takes "longer" because it takes the water longer to boil at higher alttitudes due to the lack of 02 (Oxgen). The egg, once boiling temps are reached, cooks just as quickly as at lower alttitudes. It seems longer because it takes the water to reach the point of "boiling" than at lower alttitudes. Most if this "longer to cook" is simply a trick of the mind because, the egg does in fact cook just as quickly...it's the time it takes to "reach" the "boiling-point" that actually requires more time.

Answer 11

because water boils at a lower temperature at altitude due to decreased air pressure. !00 degrees is the boiling point of water at a pressure of 1 atmosphere, at altitude the pressure is less.