If 5,100 Joules of heat are released when a sample of water freezes,what is the mass of the water?

1 Answer
Mar 5, 2018

15.3 grams


When water freezes at 0 degrees C it loses potential energy to the surroundings, without changing its temperature. This is known as the Latent Heat of Fusion of water . I.e the energy change #x# mass of water changes to #x# mass of ice under constant temperature. The same story goes for when steam at 100 degrees C condenses back to water at constant temperature, this energy change is known as the Latent Heat of Vaporization of water.

This is given by the equation:

#Q=mL # where Q is the energy released/ put in, m is the mass of the substance and L is the Latent heat of vaporization/fusion of the substance in question.

Now #Q= 5100 J#, #L= 334 J g^-1# and #m# is our uknown.

#5100=334 times m#
#m approx 15.3# grams