Chemistry, asked by sarthu, 1 year ago

 Why is latent heat of vapourisation higher than the latent heat of fusion?

Answers

Answered by tithi
104
Latent heat of vaporization is higher than latent heat of fusion because:
vaporization or change of state from liquid to gas requires higher potential energy as compared  to change of state from solid to liquid(latent heat of fusion).This is because the intermolecular space between the molecules of gases is the largest.Hence more heat is absorbed during vaporization and its causes to rise its (substances')temperature by a higher value........
hence the heat required by a substance to vaporize is more thus latent heat of vaporization is more...........:)hope i helped u 

tithi: plzzzzzzz mark as best
Answered by saniarisha
39
The latent heat of fusion and vaporization both involve the heat required to change the state of a substance without a change in temperature. In the case of the latent heat of fusion it is the heat required to change a substance from a solid (ice) to a liquid (water) or vice versa while the latent heat of vaporization from a liquid (water) to a gas (steam) or vice versa. 

In solids, the molecules are very close together and the attraction between the molecules are great. This causes a substance to have a structure in which the molecules have little freedom to move, as you would see in the case of ice. In the case of a liquid, the molecules are closely spaced, though not as closely spaced as a solid, they have more freedom to move and the intermolecular forces are weaker that that of a solid. Thus a liquid can flow, unlike a solid. Now in a gas, the molecules are sufficiently far apart that there are little to no attractive forces. Because of this a gas can easily be compressed and take the shape of the container. 

Now as you heat a solid turning it into a liquid, you increase the kinetic energy of its molecules, moving them further apart until the forces of attraction are reduced to allow it to flow freely. Keep in mind the forces of attraction still exists. Now as you heat a liquid, turning it into a gas, the kinetic energy of the molecules are increased to a point where there are no forces of attraction between the molecules. 

The energy required to completely separate the molecules, moving from liquid to gas, is much greater that if you were just to reduce their separation, solid to liquid. Hence the reason why the latent heat of vaporization is greater that the latent heat of fusion.
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