    # What is the formula of total latent heat formula?

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LATENT HEAT
•Latent heat is the energy required to change a fixed amount of substance (such as 1 mole) into a different state. ie. solid to liquid.•Over the period of time that latent heat is being absorbed, the temperature of a substance will not change (this is since the energy is being used to change state).•Latent heat values are given the symbol L and have the unit kilojoules per mole, kJmol-1.•Latent heat of fusion- heat needed to change 1 mole of the substance from a solid to a liquid at its melting point.•Latent heat of vaporisation- heat needed to change 1 mole of the substance from a liquid to a gas at its boiling point.•Latent heat of fusion of water is 6.0 kJmol-1   - This energy is used to break some of the hydrogen bonding between water molecules in the ice lattice.•Latent heat of vaporisation of water is 44.0 kJmol-1  -This energy is used to completely break the hydrogen bonds between water molecules.Calculation involving latent heat:

•The heat energy required for a state change is given by the formula:

q= n x L
Where        q is the heat energy (kJ)                    n is the amount of substance (mol)

L is the latent heat (kJmol-1)

•Calculate the heat energy, in kJ, required to evaporate 100g of water at 100oC.

n= m/M, n= 100/18 = 5.56 mol.  L = 44.0 kJmol-1 (heat of vaporisation- since   temperature is 100oC- boiling point of water)  q = n x L

q = 5.56 x 44.0 = 244kJ.

 Kahoot quiz- Specific and latent heat

Specific latent heat is energy hidden in the internal structure of a substance. As we saw in the sensible heat calculator, if we transfer heat to water, its temperature increases according to its specific heat.

Once the temperature reaches the boiling point, something interesting happens. The temperature stops increasing, and instead, the water vaporizes. This process of turning water into vapor takes some energy. This is the latent heat. Once all the water is turned into vapor, a further transfer of heat will simply increase the temperature again.

Condensation is the reverse process of vaporization, where gas turns into liquid. The latent heat released during condensation is equal to the latent heat absorbed during vaporization.

A change from a liquid to a gaseous phase is an example of a phase transition. Another common phase transition is from a solid to a liquid phase. Specific latent heat is the amount of energy absorbed or released during the phase transition per 1 kg of the substance. 