From the data attained from the experiments, the latent heat of fusion of ice is 3.
63 x 105 Jkg-1 with an uncertainty of 0. 314 x 105 Jkg-1. This result was calculated by applying the law of conservation of energy, which states that energy will not be distorted nor created. Thus, we can say that the loss of energy of hot water is equal to gain of energy of ice. In the calculation, we have used the theoretic values of specific heat capacity of ice and water from the text book, Giancoli, and use the formulae E=mc??and E= ml. From that we found out the latent heat of fusion in each of the observations.
Compared to the theoretic value 333000 Jkg-1, we can see that the average result from the experiment (3. 63 x 105 Jkg-1) is acceptable. (? The theoretic value lies between the uncertainty borders of the calculated result. ) This shows that our result supports the theory.
Evaluation Since the result is not exactly the same as the theoretic value of latent heat of fusion of ice, we can assume that there are errors within the experiment.Firstly, there were uncertainties in the every measurement, which contributed to the systematic errors in calculation. Secondly, the cover lid for the calorimeter is often too small to cover the mouth of the cup. Therefore, there was heat loss from the water and thus the calculated value would be larger.
This was another systematic error. Thirdly, due to the small size of the lid as well, it often falls and touches the water. This created random errors.On top of that, even though we used another foam cup to act as an insulator to heat, there’s heat loss to surrounding and heat absorbed by the cups. It was systematic error again. On the other side, the exact temperature of the ice was not accurately measured due to the insensitivity of the thermometer.
Thus, systematic errors occurred. In order to improve the accuracy and precision of the experiment, we should use a more sophisticated metal calorimeter instead of one that is made by foam cups only.This can help reducing unnecessary heat loss to the surrounding and minimize other random errors like lids falling down. Moreover, we should use measuring apparatus with smaller least counts, so that the uncertainties of measurement will be smaller.
Besides, we should use a more sensitive thermometer in low temperature to get the actual temperature of the ice, so that the deviation of recorded and actual temperature will be smaller. i The emboldened tables are the data collected. The remaining ones are the data calculated from the collected data.