What is the unit of latent heat of evaporation?

May 17, 2019 Off By idswater

What is the unit of latent heat of evaporation?

The latent heat of vaporization is a physical attribute of a substance. It is defined as the heat required to transform one mole of liquid at its boiling point under some standard atmospheric pressure. It is expressed in Kg/mole or KJ/KG.

What are the SI units for latent heat?

is a measure of the heat energy (Q) per mass (m) released or absorbed during a phase change. is defined through the formula Q = mL. is often just called the “latent heat” of the material. uses the SI unit joule per kilogram [J/kg].

What is the unit of latent heat and specific heat?

Specific latent heat Q is the amount of energy released or absorbed during the change of phase of the substance (in kJ or in BTU), m is the mass of the substance (in kg or in lb), and. L is the specific latent heat for a particular substance (kJ kg−1 or in BTU lb−1), either Lf for fusion, or Lv for vaporization.

What is the SI unit of latent?

The SI unit of latent heat is Joule per Kilogram.

What is called latent heat?

latent heat, energy absorbed or released by a substance during a change in its physical state (phase) that occurs without changing its temperature. The latent heat is normally expressed as the amount of heat (in units of joules or calories) per mole or unit mass of the substance undergoing a change of state.

How do you calculate latent heat?

Latent heat calculation The specific latent heat is different for solid to liquid transition and liquid to gas transition. For example, if we want to turn 20 g of ice into water we need Q = 20 g * 334 kJ/kg = 6680 J of energy. To turn the same amount of water into vapor we need Q = 45294 J .

What is the dimensional formula of latent heat?

Or, L = [M1 L2 T-2] × [M1 L0 T0]-1 = [M0 L2 T-2]. Therefore, latent heat is dimensionally represented as [M0 L2 T-2].

How do you calculate specific latent heat?

Calculations involving specific latent heat

  1. l f = 3 ⋅ 34 × 10 5 J k g − 1 for fusion (solid→liquid) or freezing (liquid→solid)
  2. l v = 22 ⋅ 64 × 10 5 J k g − 1 for vaporisation (liquid→gas) or condensation (gas→liquid)

How can you detect latent heat?

Measuring latent heat Latent heat can be measured from a heating or cooling curve line graph. If a heater of known power is used, such as a 60 W immersion heater that provides 60 J/s, the temperature of a known mass of ice can be monitored each second.

Why it is called latent heat?

Latent heat, also called heat of transformation, is the heat given up or absorbed by a unit mass of a substance as it changes from a solid to a liquid, from a liquid to a gas, or the reverse of either of these changes. It is called latent because it is not associated with a change in temperature.

What are some examples of latent heat?

Examples of Latent and Sensible Heat

  • Boiling water on a stove occurs when thermal energy from the heating element is transferred to the pot and in turn to the water.
  • Similarly, considerable energy must be absorbed to convert liquid water to ice in a freezer.
  • Latent heat causes hurricanes to intensify.

Which is the SI unit of specific latent heat?

SI unit of specific latent heat of fusion, lf, is joule per kilogram (Jkg-1) $Q = ml_{f}$, where. Q = amount of thermal energy absorbed or released. m = mass of substace. lf = specific latent heat of fusion.

What is the latent heat of evaporation for water?

The latent heat of evaporation for water is 2256 kJ/kg at atmospheric pressure and 100oC. The heat required to evaporate 10 kg can be calculated as q = (2256 kJ/kg) (10 kg) = 22560 kJ

How is the specific latent heat of fusion defined?

Specific latent heat of fusion, l f, of a substance is defined as the amount of heat required to change a unit mass of the substance from solid to liquid state, without any change in the temperature. SI unit of specific latent heat of fusion, l f, is joule per kilogram (Jkg -1)

When does the latent heat of vaporization disappear?

Latent Heat of Vaporization The heat of vaporization diminishes with increasing pressure, while the boiling point increases. It vanishes completely at a certain point called the critical point. In general, when a material changes phase from solid to liquid, or from liquid to gas a certain amount of energy is involved in this change of phase.