- The heat required for a substance to change phase (like melting) at a constant temperature is given by the formula Q = m L, where Q is the heat energy, m is the mass, and L is the latent heat of fusion (for melting) or vaporization (for boiling). - Given mass of ice m = 100 g. - Given latent heat of melting of ice L = 333.6 J/g. - Heat required Q = 100 g 333.6 J/g = 33360 J.
A piece of ice, 100 g in mass is kept at 0 °C. The amount of heat it requires to melt at 0 °C is (take latent heat of melting of ice to be 333.6 J/ g):
Asked in UPSC CDS 1 2016 · Topic: Heat and Thermodynamics (Calorimetry and Phase Changes (Specific Heat, Latent Heat))
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