# What is the Value of Latent Heat of Steam?

##### Joseph Hebert
Owner at - HVAC Buster

Joseph is an HVAC technician and a hobbyist blogger. He’s been working as an HVAC technician for almost 13 years, and he started blogging just...Read more

Latent heat of steam is the energy required to change water into steam without affecting its temperature. The value of latent heat of steam can be determined by measuring the amount of heat required to raise the temperature of a given quantity of water from its freezing point to its boiling point. This value is important for understanding how much energy is needed to produce steam, and how much work can be done by steam at a given temperature.

The latent heat of steam is the energy that is required to change water into steam. This energy is released when the steam condenses back into water. The latent heat of steam can be used to power turbines and engines, and it can also be used to heat buildings and homes.

The latent heat of steam is a valuable resource that can be harnessed to improve our lives.

## What is the Value of Latent Heat?

When water is heated, it first expands as its temperature rises. But there comes a point where the continued addition of heat does not result in a further increase in temperature; rather, the water begins to vaporize. The temperature at which this changeover from liquid to gas occurs is called the boiling point.

The heat required to bring about this change of state is known as latent heat (of vaporization). The value of latent heat can be experimentally determined by measuring the amount of heat required to raise the temperature of a sample of water from, say, 20°C to 21°C. This would give the specific latent heat (slh) for water at 20°C—that is, the amount of heat required per unit mass to convert it from a liquid into a gas at that particular temperature.

The SI units for specific latent heat are joules per kilogram (J/kg). The table below shows values of slh for water over a range of temperatures. At higher temperatures, more and more energy is required to overcome attractions between molecules and so break them apart into vapour molecules.

So, specific latent heats generally increase with increasing temperature—except very close to the boiling point where they reach their maximum value (the enthalpy of vaporization) and then start decreasing again because some molecules now have enough kinetic energy to escape without taking any additional input energy (heat). For example, when water boils at 100°C under standard atmospheric pressure (101 kPa or 1 atmosphere), about 2260 J/kg (540 cal/g) of energy are needed just to break up the intermolecular attractions holding together its molecules in the liquid state; after that only an extra few joules are needed per molecule for it acquire enough kinetic energy to become vapour. That’s why steam above 100°C has much less capacity than cold water or even warm water below 100°Cto transfer heat by convection: almost all its internal energy is in the form kinetic energies acquired during vaporization and so cannot be used directly for convection until it condenses back into liquid form again.

## Does Steam Have Latent Heat?

Yes, steam does have latent heat. Latent heat is the energy released or absorbed by a substance during a change in phase. The latent heat of vaporization is the amount of heat required to convert a unit mass of a liquid into a vapor at constant temperature.

For water, the latent heat of vaporization is 2260 kJ/kg. This means that it takes 2260 kJ of energy to turn 1 kg of water into steam. The latent heat of condensation is the amount of heat required to convert a unit mass of vapor into a liquid at constant temperature.

For water, the latent heat of condensation is 2256 kJ/kg. This means that it takes 2256 kJ of energy to turn 1 kg of steam back into water.

## What is Latent Heat of Vapour?

Latent heat of vapourisation (the latent heat of vaporization or LTV) is the amount of thermal energy required to transform a given quantity of a substance from a liquid into a gas at constant temperature and pressure. The enthalpy of vaporization is usually expressed in J/mol or kJ/kg. The enthalpy change for the vaporization process can be measured using calorimetry, with the known value then used to calculate the unknown latent heat.

In thermodynamics, latent heat is the energy released or absorbed by a body or system during a change in phase. For example, when water boils and turns to steam, it releases latent heat that had been stored in the liquid phase. Similarly, when steam condenses back into water, it absorbs latent heat from its surroundings.

The concept of latent heat was developed over time by several scientists including Josiah Wedgwood, Benjamin Thompson (Count Rumford), and James Prescott Joule. The term “latent” comes from the Latin word latens which means “lying hidden”. In contrast to sensible heat (heat that results in a temperature change), which is readily observed on feeling an object’s temperature with one’s hand, there may be no obvious sign that latent heat has been exchanged except for changes in state such as boiling or freezing.

## What is the Value of Latent Heat of Vaporization in Calories?

Latent heat of vaporization is the amount of heat required to change a substance from a liquid to a gas. The value of latent heat of vaporization is different for each substance and is usually expressed in calories per gram (cal/g). For water, the latent heat of vaporization is 539 cal/g.

This means that it takes 539 calories of energy to transform one gram of water from a liquid to a gas. The latent heat of vaporization has a number of uses. It can be used to measure the purity of a substance, since more impure substances have lower latent heats of vaporization.

It can also be used in refrigeration and air conditioning systems, as it takes much less energy to evaporate a substance than it does to raise its temperature. Overall, the latent heat of vaporization is an important property that can tell us a lot about a substance and how it will behave under different conditions.

## Latent Heat of Vaporization of Steam in Cal/G

The latent heat of vaporization of steam is the heat required to change water into steam at a constant temperature. It is also known as the heat of evaporation or the enthalpy of vaporization. The latent heat of vaporization is important in many applications, including power generation and desalination.

The value of the latent heat of vaporization varies depending on the pressure and temperature at which it is measured. The higher the pressure, the higher the latent heat of vaporization. For example, at atmospheric pressure, the latent heat of vaporization is about 2200 cal/g.

However, at 10 atmospheres (100 kPa), the latent heat of vaporization increases to about 2700 cal/g. The temperature also affects the value of the latent heat of vaporization. As the temperature decreases, so does the latent heat of vaporization.

For example, at 0°C (273 K), the latent heatofvaporizationis about 2260 cal/g. However,at-100°C (-173 K),thelatentheatofvaporizations drops to about 1600 cal/g. Knowingthevalueofthelatentheatofvaporization can be helpful in many situations.

For instance, when designing a boilerforasteampowerplant, engineers needto account forthe lossofenergy that occurswhen waterchanges into steam.

## Latent Heat of Vaporization of Steam in J/Kg

The latent heat of vaporization is the amount of heat required to change a substance from a liquid to a gas. The latent heat of vaporization for water is 2,260 J/kg. This means that it takes 2,260 Joules of energy to convert 1 kilogram of water from a liquid to a gas.

The latent heat of vaporization is also known as the enthalpy of vaporization or the heat of vaporization.

## Latent Heat of Steam at 100 Deg C

The latent heat of steam at 100 degrees Celsius is 226 kJ/kg. This means that it takes this much energy to change 1 kg of water into steam at this temperature. The latent heat of steam is important to know because it can be used to help calculate the amount of energy needed to raise the temperature of water or steam.

For example, if you wanted to raise the temperature of 1 kg of water from 20 degrees Celsius to 100 degrees Celsius, you would need to add (100-20)*4.2 kJ + 226 kJ = 804.2 kJ of energy.

## Latent Heat of Steam Formula

When water is heated, it first turns to steam at 100°C. However, the temperature of steam can continue to rise well above this without any further change in state occurring. The heat that is added to water when it changes from a liquid into a gas is called latent heat of vaporization or enthalpy of vaporization and is represented by the symbol ΔHvap.

The amount of heat required to turn 1 kg of water into steam at 100°C is 2,257 kJ/kg. The formula for latent heat of steam can be derived from the first law of thermodynamics and is given by: ΔHvap = m (hg – hf)

Where: ΔHvap = latent heat of vaporization (kJ/kg) m = mass flow rate (kg/s)

hg = enthalpy of saturated steam (kJ/kg)

## Conclusion

The latent heat of steam is the energy that is released when water vapor condenses into liquid water. This heat can be used to power turbines and other machinery, or it can be used to heat buildings and homes. The latent heat of steam is a valuable resource that can be harnessed to improve our lives.

Joseph is an HVAC technician and a hobbyist blogger. He’s been working as an HVAC technician for almost 13 years, and he started blogging just a couple of years ago. Joseph loves to talk about HVAC devices, their uses, maintenance, installation, fixing, and different problems people face with their HVAC devices. He created Hvacbuster to share his knowledge and decade of experiences with people who don’t have any prior knowledge about these devices.