How many BTU's does it take to evaporate one pound of water?

Answer 1

BTUs to Evaporate One Pound of WaterQuick Answer: Somewhere around 1000BTU/lb

Long answer: It depends on the temperature of the water you start with. Before you can evaporate the water, you must heat it to it's boiling point. The warmer the water you start with the fewer BTUs will be needed to heat the water to its boiling point. Keep in mind the BTUs require to raise the water to its boiling point are very few compared to the BTUs required to change the water from a liquid to a gas.

One pound of steam contains 1150 BTUs. This is the energy you need to put into the water for it to evaporate if you start with water at 32F. If you start with water at 100F the water already has 70 BTU/lb so the BTUs required to evaporate the water when you start at 100F is 1150-70 = 1080 BTU and so on.

You can get all this information in a steam table which can be found easily by searching the web.

Answer 2

To evaporate one pound of water, it takes approximately 970.4 BTUs (British Thermal Units). This specific amount of energy is required to change the state of water from liquid to vapor at its boiling point, which is 212 degrees Fahrenheit (100 degrees Celsius). This process involves breaking the intermolecular bonds between water molecules and overcoming the latent heat of vaporization.

Answer 3

Well honey, it takes 970 BTUs to evaporate one pound of water. So if you're planning on turning that H2O into steam, you better have your BTUs ready to go. Just remember, a watched pot never boils, but with enough heat, that water will be gone before you can say "Betty White is a national treasure."

Answer 4

Oh, dude, you're asking me about BTUs and water evaporation? Like, who even knows that stuff off the top of their head? But hey, lucky for you, I happen to know that it takes about 970 BTUs to evaporate one pound of water. So, there you go, knowledge dropped.

Answer 5

Any amount of heat will evaporate water, it just takes longer with less heat.

I'm leaving the above answer to illustrate a common misunderstanding. "Heat" in chemistry and physics has a specific meaning that may be different from what most people mean by heal.

The specific heat of vaporization of water is about 2250 kJ per kilogram. This is quite close to 1 megajoule (1000 kJ) per pound.

Answer 6

Quick Answer: About 2,139 BTU/litre at the normal boiling point.

Long answer: It depends on the temperature and pressure of the water you start with. Before you can evaporate the water, you must heat it to it's boiling point. The warmer the water you start with the fewer BTUs will be needed to heat the water to its boiling point. Keep in mind the BTUs require to raise the water to its boiling point are very few compared to the BTUs required to change the water from a liquid to a gas.

One litre of water weighs about 2.205 lb, and since both BTUs and lb are from the imperial set of units, we can make the rest of this explanation in terms of pounds and then just multiply by 2.205 when we get done.

One pound of steam contains 1150 BTU/lb relative to liquid water at 32 °F. This is the energy you need to put into the water for it to evaporate if you start with water at 32 °F. If you start with water at 100 °F the water already has 70 BTU/lb so the BTUs required to evaporate the water when you start at 100 °F is 1150-70 = 1080 BTU/lb and so on.

You can get all this information in a steam table which can be found easily by searching the web.

Answer 7

The water heat of vaporization is 40,65 kJ/mol.