John Marrero Roman
Nicolas Viera & Caroline Shinkoff
Lab Instructor: Alexandra Chabot
October 19, 2022
Lab 6 - Heat of Fusion of Water
Abstract:
The goal of this experiment is to find the latent heat of fusion of water. This is done by
achieving thermal equilibrium after adding water and ice to a calorimeter. As ice heats up, it will
eventually reach its melting point and begin to melt as long as heat is continuously applied to it.
Once the ice reaches its melting point, the ice does not heat up more and will melt into water and
once it completely changes phases, the water will then continue to rise in temperature while heat
is still being applied. The heat of fusion of ice is the heat that is required per unit mass to melt
the ice into water.
Data:
Table 1.1: Heat of Fusion of Water masses and temperatures measurements
Mass of Calorimeter Cup and Stirrer (kg)
.05571
Mass of Entire Calorimeter (kg)
.3155
Temperature of Room (°C)
23.5
Mass of Entire Calorimeter and Water (kg)
.4845
Temperature of H2O (°C)
52.6
Mass of Ice (kg)
.0281
Mass of Calorimeter, Water, and Ice (kg)
.51251
Table 1.2: Time vs. Temp measured Data
Time
(s)
Temperature
(°C)
0
31.2
30
16.5
60
16.5
90
16.6
Figure 1.1: Temperature vs. Time graph
Data analysis:
Initially in the graph, there is a sharp fall from 31.2OC in t=0s to 16.5OC in t=30s. Then
there are some variations in the form of plateaus and rise until the final temperature reaches
16.6OC. When ice is added to hot water/solution, a part of the heat from the water/ solution melts
the ice. This causes the initial drop in the temperature. However, the rest of the water/ solution is
still warm. The residual heat from this water heats the melted ice. This in turn cools the hot
water. The results appear as plateaus and rise. After some time, the final temperature is attained
which is the same as the ambient temperature.
Here in Figure 1.1, it is assumed the exchange of heat between two systems is according
to the temperature difference between them. That is heat flows from Ti to Tf. The heat flows with
a stop when the thermal equilibrium is established.
Using the data obtained from the experiment and equation (3) from the manual,
𝑚𝑐 𝑐𝑐 ∆𝑇𝑐 + 𝑚𝑤 𝑐𝑤 ∆𝑇𝑤 + 𝑚𝐼 𝐿𝑓 + 𝑚𝐼 𝑐𝐼 ∆𝑇𝐼 = 0
(0. 05571𝑘𝑔)(900 𝐽/(𝑘𝑔°𝐶))(16. 6°𝐶 − 31. 2°𝐶)
+ (0. 169𝑘𝑔)(4186 𝐽/(𝑘𝑔°𝐶))(16. 6°𝐶 − 31. 2°𝐶)
+ (0. 0281𝑘𝑔)𝐿𝑓
+ (0. 0281𝑘𝑔)(4186 𝐽/(𝑘𝑔°𝐶))(16. 6°𝐶 − 31. 2°𝐶) = 0
5
𝐿𝑓 = 3. 85242 × 10 𝐽/(𝑘𝑔)
𝐿𝑓 = 385. 242 𝑘𝐽/(𝑘𝑔)
Conclusion:
Although this experiment was fairly short, it is very easy to mess up due to the many
errors that can occur in this lab. It is important to be aware of how much ice goes into the system,
as well as the temperature of the water put into the calorimeter. In conclusion, the experimentally
determined latent heat of fusion of water constant was 385.242 kJ/kg and did not agree with the
theoretical value of the latent heat of fusion of water constant due to the uncertainty of the
experimentally determined value. In the future, this procedure could be modified by adding a
little less ice in order to get closer to the theoretical value of the constant.