Chapter: Heat and Its Transmission
The specific latent heat of vaporization of asubstance is the quantity of heat needed tochange unit mass from
The specific latent heat of vaporization, \( L_v \), is defined as the amount of heat needed to change a unit mass of a substance from liquid to vapour at constant temperature.
The formula for specific latent heat can be expressed as:
Where:
In the case of vaporization, heat energy is supplied to the liquid, causing the molecules to overcome intermolecular forces and escape as vapor without a temperature change.
Option (a): Incorrect because it implies a change in temperature during the phase transition.
Option (c): Incorrect; it describes condensation, which is the reverse process.
Option (d): Incorrect as it also refers to a temperature change associated with condensation.
Remember "Vaporization = Vapor at Constant Temp" (V = VCT) to connect the concept with the definitions.
A phase change diagram depicting the heating curve of a substance, showing temperature versus heat added, illustrating the horizontal line representing the latent heat phase (vaporization) at constant temperature.
Verified against NCERT Class XI Physics, Chapter 12 (Thermodynamics).
The quantity of heat needed to change unit mass of a substance from liquid to vapour without changing the temperature, is called
The process of changing a substance from a liquid to a vapor at constant temperature is defined by the concept of latent heat.
The specific latent heat (\( L \)) is defined as the amount of heat required to convert a unit mass of a substance from one phase to another without a change in temperature. The formula is:
Where:
Remember: Latent means hidden; Latent Heat is the "hidden" energy required for phase changes.
A phase change diagram could illustrate the process of boiling water, showing the input of heat energy while maintaining constant temperature during vaporization.
Verified against NCERT Class XI Physics, Chapter 11 (Thermal Properties of Matter).
This is a preview of the SenaPrep Question Bank. To access comprehensive chapter-wise exercises, bookmark questions, attempt custom tests, and track your progress, download the official SenaPrep Android App.
Download Android App
SENAPREP