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प्रश्न
Why does the temperature of a substance remain constant during its melting point or boiling point?
उत्तर
When a substance melts, it absorbs heat for the conversion of the solid state into a liquid state. As we continue heating, the heat supplied is used up in converting the solid state into a liquid state by overcoming the forces of attraction between the particles and there is no change in temperature till the whole solid is converted into liquid. This heat absorbed by the solid which does not result in an increase in temperature is called the latent heat of fusion. When a liquid is heated, it starts converting into vapours.
Further heat given to the liquid is used in changing the state and there is no increase in the temperature till the liquid starts boiling. This heat is known as the latent heat of vaporisation. Hence, the temperature of a substance remains constant at its melting point or boiling point until all the substance melts or boils.
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संबंधित प्रश्न
Explain the terms boiling point.
Boiling of egg results in ______ change.
Assertion: The process of conversion of liquid water to its vapours by heating the liquid is called boiling.
Reason: The process of conversion of water vapours to liquid by cooling the vapours is called condensation.
What is the physical state of water at 100°C.
Choose the correct statement of the following
Evaporation of a liquid at room temperature leads to a ____________ effect.
The phenomenon of change of a liquid into the gaseous state at any temperature below its boiling point is called ____________.
Conversion of solid to vapour is called sublimation. Name the term used to denote the conversion of vapour to solid.
Assertion (A): No-new substance is formed when water is heated to get steam.
Reason (R): Conversion of water into steam is a physical change.
Explain the terms boiling.
