Measuring the Specific Latent Heat of Fusing of Ice
- Figure above shows the apparatus setup to determine the specific latent heat of fusion of ice. Some ice at 0 °C is heated by a small electric heater which is left switched on for several minutes.
- Some of the ice melts to form water which runs down through the funnel and is collected in the beaker.
- The mass of ice (m) melted is found by measuring the mass of water collected.
- If the power of the heater is P and the time taken to heat the ice = t, then the thermal energy supplied by the heater = thermal energy used to melt ice = Pt.
Therefore, the specific latent heat of fusion of iceL= Pt m
- The heating element of the heater must fully immerse in ice so that all the heat generated is absorbed by the ice.
- A control set is needed to estimate the amount of mass of ice melted by the heat from the surrounding.
- The heat received by ice is less than the calculated value Pt as some heat is lost to the surrounding. This will result in the value of l obtained from the calculation to be slightly higher than the standard value.
- If impurity is present in water, the melting point of the water will be lower than normal.