Skip to main content

Temperature doesn't change during phase change( melting, boiling etc..). Why?

The heat added to the solid is absorbed by the particles and it is utilised in overcoming the intermolecular force of attraction between the particles. So heat absorbed in solids is changed to potential energy without any change in kinetic energy of the molecules. As temperature in Kelvin scale is the measure of kinetic energy of particles, there is no change in temperature during melting.

Comments

Popular posts from this blog

What is loudness of a sound?

Loudness of a sound is the characteristic of a sound which depend on the intensity of  energy it carries. Intensity of a sound is the amount of energy passing through a surface area of one square metre held perpendicular per sec. Intensity depends on square of amplitude of the wave passing. Hence we can say Loudness is directly proportional to the square of Amplitude. If amplitude is doubled, loudness becomes four times. Loudness depends on distance of source from the listener. Loudness depends on resonance also.

Why is food cooked faster in pressure cooker?

Water boils at 100°C at normal pressure of 1 arm or 100000 Pascal. Boiling temperature increases  with the increase in pressure above the liquid surface. When we cook food in pressure cooker, the pressure increases due the retention of vapour and hence the boiling temperature increases in the pressure cooker upto 125°C As food is cooked at higher temperature than 100°C , it is cooked faster in the pressure cooker.