amount of energy it takes to boil water
Yes, but it depends. Boiling point represents a phase change of matter. Water molecules will require sufficient energy (kinetic energy) to escape the liquid phase and accelerate into the vapor phase. More water simply means more energy is required to bring about the phase change, however the boiling point temperature will remain fixed. In other words, the amount of energy required to undergo phase change for every individual H2O molecule is always the same, but more molecules means more energy input is required. Once the water is at 100 °C, still more energy must be added. This is given by the heat of vaporization, which for water is 2261 kJoules per kilogram. So, in the example, once the 1 kg of water. is at 100 °C, this amount of energy must be added to boil it: 1 kg * 2261 KJoules/kilogram = 2261 kJoules. What c in the equation is, the specific heat capacity. So in water it takes 1200 joule's to raise a Kg of water by 1 degree K or in degrees C. So the answer is Delta T equals 20 degrees C to 100 degrees C assuming the water is at room temperature. So Delta T =80. First, the water must be heated to 100 °C, which takes energy. The amount of energy is given by the specific heat of water, which is 4.186 Joule/gram °C. That means that requires 4.186 Joules of energy to heat 1 kilogram of water by 1 °C. So if you have 1 kg of water at 20 °C, you have to add this much energy: If you also wanted to convert the water to steam, you'd have to add the latent heat of vaporization to that, which is Q = mL. The latent heat of vaporization for water is 2260 KJ/kg, so the additional energy required is (3.785 kg)(2260 KJ/kg) = 8554 KJ, for a total of 9819 KJ. How much energy (in calories and in Joules) will it take to raise the temperature of 75.0 g of water from 20.0 to 55.0 oC? ( Specific Heat = 1 cal / ( g oC ) and 4.184 J / ( g oC ) ) 2630 cal and 630. 630. None of these are correct. The quantity of heat required to change the temperature of 1 gram of a substance by 1 degree Celsius. What does the change of a substance's phase involve. The changing of a substance form a solid to a liquid to a gas, for example, involves the breaking of molecular attractions. What is the heat of melting. The heat energy absorbed by a substance as it transforms from solid to liquid. For water this is +335 joules per gram. How much energy (in calories and in Joules) will it take to raise the temperature of 75.0 g of water from 20.0 to 55.0 oC? ( Specific Heat = 1 cal / ( g oC ) and 4.184 J / ( g oC ) ) 2630 cal and 630. J. 2630 cal and 1.1 x 10 4 J. 1.1 x 10 4 cal and 2630 J. If this takes 1 min to boil the power required to boil the water equals 96kilo joules/60 seconds =1600 watts or 1.6 kilo watts. Dividing this by 60 into minutes and then by 60 again into hours gives the answer in kilo watt hours as what appears on your energy bill. 0.444 kilo watt hours. One gallon of water is 3.785 liters, which has a mass, it turns out, of 3.785 kg. The specific heat of water is 4.179 J/(gK), or 4719 J/(kgK). Let's say that room temperature is about 20 degrees Celsius. To boil water, we have to get it to 100 degrees celsius, for a δT of 80 degrees Celsius (or 80 Kelvins).
2261 kJoules