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The amount of heat that must be removed from steam to change it to a liquid is the latent heat of vaporization of water, which is approximately 2260 kJ/kg at atmospheric pressure. This is the amount of energy required for water to change from a gas to a liquid state at a constant temperature.
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What change of state happens when heat is removed from water and it condenses?
When heat is removed from water, it undergoes a change of state from a gas (water vapor) to a liquid (water). This process is known as condensation.
How does the amount of heat required to change water from a solid to a liquid compare with the amount needed to change from a liquid to a gas?
Very simply, the amount of heat required to change state is exactly the same for solid to liquid (ice to water) and liquid to gas (water to steam) for a given substance, in this case water. The basic measurement of heat is the BTU (British Thermal Unit). 1 BTU is the quantity of heat required to raise 1 pound of water 1 degree Fahrenheit at atmospheric pressure. Keep in mind that there are two 'types' of heat to consider when contemplating the change of state of a substance: Sensible heat and latent heat. Clearly, sensible heat we can measure directly with a thermometer. Latent heat is a calculated quantity. When water undergoes the change of state from water to steam (liquid to gas) it does so through the gain of heat quantity. That heat gain that causes the change of state is latent heat, i.e; the actual heat gain is unmeasurable by thermometer since the temperature of that water is 212 deg f as it undergoes the change of state to steam, and that steam is also 212 deg f. Any increase in the temperature of the steam is said to 'superheat' the steam. As an example, steam fed boilers are nearly always supplied with 'superheated' steam at temperatures near 600 deg f. We see the addition of heat quantity as sensible heat during the rise of the waters temperature to 212 deg f (we are able to measure the rise in temperature), then we see the addition of heat quantity as latent heat during the change of state to gas from liquid (no change in the measurable temperature during the change of state), and again the addition of heat quantity as sensible heat in the process of 'superheating' the steam to any temperature above 212 deg f. If you can quantify the amount of water in pounds, you can quantify the amount of heat in BTU's.
Does physical change occur when energy is added or removed?
Physical change can occur when energy is added or removed. For example, adding heat energy can cause water to change from a solid to a liquid (melting), while removing heat energy can cause water to change from a liquid to a solid (freezing). These changes do not alter the chemical composition of the substance.
What has the more heat energy at 100 degrees Celsius water or steam?
steam. It has to go through a phase change, which takes additional energy to get there.
How hot water changes to steam is?
When water is heated, the energy from the heat causes the water molecules to move faster and break free from the liquid phase, forming steam. This process is known as evaporation. As more heat is applied, the water molecules gain enough energy to overcome the intermolecular forces holding them in the liquid phase, resulting in a phase change from liquid water to gaseous steam.
What change of state happens when heat is removed from water and it condenses?
When heat is removed from water, it undergoes a change of state from a gas (water vapor) to a liquid (water). This process is known as condensation.
The process of steam condensing to form liquid water is?
The process of steam condensing to form liquid water involves the transfer of heat energy from the steam to the surrounding cooler environment. As the steam loses heat, its temperature decreases and it undergoes a phase change from gas to liquid. This results in the formation of liquid water droplets.
How is steam created?
steam is created by the vapourisation of water (gaseous state of water is the steam). Steam is the result of a liquid changing to a gas. Liquid+heat=latent point of vaporization+additonal heat=steam. I could give you the delta change formula but lets use the kiss method
How does the amount of heat required to change water from a solid to a liquid compare with the amount needed to change from a liquid to a gas?
Very simply, the amount of heat required to change state is exactly the same for solid to liquid (ice to water) and liquid to gas (water to steam) for a given substance, in this case water. The basic measurement of heat is the BTU (British Thermal Unit). 1 BTU is the quantity of heat required to raise 1 pound of water 1 degree Fahrenheit at atmospheric pressure. Keep in mind that there are two 'types' of heat to consider when contemplating the change of state of a substance: Sensible heat and latent heat. Clearly, sensible heat we can measure directly with a thermometer. Latent heat is a calculated quantity. When water undergoes the change of state from water to steam (liquid to gas) it does so through the gain of heat quantity. That heat gain that causes the change of state is latent heat, i.e; the actual heat gain is unmeasurable by thermometer since the temperature of that water is 212 deg f as it undergoes the change of state to steam, and that steam is also 212 deg f. Any increase in the temperature of the steam is said to 'superheat' the steam. As an example, steam fed boilers are nearly always supplied with 'superheated' steam at temperatures near 600 deg f. We see the addition of heat quantity as sensible heat during the rise of the waters temperature to 212 deg f (we are able to measure the rise in temperature), then we see the addition of heat quantity as latent heat during the change of state to gas from liquid (no change in the measurable temperature during the change of state), and again the addition of heat quantity as sensible heat in the process of 'superheating' the steam to any temperature above 212 deg f. If you can quantify the amount of water in pounds, you can quantify the amount of heat in BTU's.
Solid ice will change to liquid water and then to gaseous steam when you add what?
Energy because energy can be used as heat.
When heat is added to or removed from a substance it may change its state. What state will most likely result if heat is added to a liquid?
In that case, the liquid may eventually change to a gas.
Is condensation an example of a phase change?
Yes, condensation is an example of a phase change. It is the process in which a gas changes to a liquid as heat is removed.
Do you need to increase or decrease the amount of heat energy to change a solid to a liquid?
Thermal (heat) energy must be added or removed in order to cause a change of state.
How do you use steam tables?
The steam tables have 16 columns as follows: pressure (absolute), temperature, specific volume of vapor, specific volume of liquid, heat of the liquid, heat of vaporization, total heat of the vapor, entropy of the liquid, entropy of vaporization, entropy of the vapor, internal heat of the liquid, internal heat of vaporization, and internal heat of the vapor (occasionally the external heat of the liquid, vaporization and vapor are included) If the temperature and pressure of steam are known then cross referencing the heat or the volume of a known quantity of the steam can be done. the heat content(enthalpy) of the liquid or vapor can be extrapolated from the chart, as can the entropy and internal energy. The enthalpy less the internal energy = the external energy (or the actual energy required to expand the liquid to a vapor) By determining the starting heat content of steam and final or exhaust heat content of steam the efficiency of a steam engine can be determined. Along with these calculations are the determinations of heat losses, steam quality, loss to entropy,...etc. all calculated using various instruments and the steam tables.
Why is heat trasnfer coefficient of saturated steam is higher than superheated steam?
when steam is at its saturation point for a given pressure, any heat removed will cause liquid water to form. So when saturated steam is used to heat something else, the heated object/substance receives the condensation heat of the steam. The latent heat of condensation/evaporation is 970 But/lb @ 0 psig. On the other, superheated steam only gives up about 10 BTU/lb if it is cooled 20 degrees F. That means that much more steam would be used to transfer the equivalent amount of heat. The liquid water interface also improves the heat transfer.
Does physical change occur when energy is added or removed?
Physical change can occur when energy is added or removed. For example, adding heat energy can cause water to change from a solid to a liquid (melting), while removing heat energy can cause water to change from a liquid to a solid (freezing). These changes do not alter the chemical composition of the substance.
When heating a liquid what phase does it change into?
Assuming enough heat is applied to the liquid for it to change phases, gas is what comes next. An example would be steam rising off of a pot of boiling water.
