Purpose: The purpose of this experiment is to find the delta heat for water.
Procedure: 1) start with 100ml of water on a hot plate and make sure it is at 50 Celsius
2) Place into foam cup and record the temperature
3) Drop 2-3 ice cubes in and stir but don't run out of ice. If ice melts add more
4) Once temp stabilizes around 0 Celsius and remove ice
5) Measure new volume of the water
Data Table:
0 minutes 50 Celsius
1 minute 5 Celsius
2 minutes 3 Celsius
3 minutes 3 Celsius
4 minutes 0 Celsius
Starting Water: 100g
Ice water with cup: 165.46g
Cup: 7.49
Ice water: 157.97
Calculate:
1) mass of 100ml of water
100ml=100g
2) Calculate q = m x delta t x c
q= 100 g x 50 x 50 C= 250,000
3) Determine q ice
flip sign -250,00
4) Mass of ice melted
57.97 g
5) Moles of ice melted
57.97(1 mol/18)= 3.22
6) delta H fusion for ice kj
3.22 1 mol H2O
250,000jk x
7) delta H = 6.01 kj/mol
Conclusion:
If 100ml water is cooled to 0 Celsius with ice then the delta H will equal about 6.01 kj/mol because delta H for water is 6.01 kj/mol. This does support the hypothesis. This experiment went well except the cup had a small leak so it had to be plugged with fingers which could have contributed extra heat. Also it never was exactly 0 degrees. This experiment was successful because water was cooled to 0 Celsius the delta heat was found being about 6.01 kj/mol.
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