The last two homework assignments

Homework Problems

Worksheet that we did in class. You know the one.

Entropy worksheet

Lab

Heat of Fusion of Ice

Purpose: Calculate delta H for ice. 

Procedure:

1: Measure 100ml H2O at 50 degrees C. 

2:  Place in styrofoam cup. 

3: Drop 2-3 ice cubes in. 

4: Stir until temp. drops to around 0 degrees C. 

5: Remove any unmelted ice

6: Measure new volume. 

Data:

100-147ml

Water Q=-17.6

Ice Q= 17.6

Mass of ice: 47g

Moles of ice: 47/18=2.6

Delta H of fusion of ice: 6.76 kJ/mol

17.6kJ/2.6mol

Conclusion: 

We found the energy required for the fusion of ice was 6.76 K/mol. Theoretically, the value should be 6.01. This yields an 11% error. A cause for this could be the failure of our thermometer to display results below 7 degrees.  

Homework