1. Name: Diane Guo
Partners: Ana Cristina, Lawrence
Date of experiment: 2010-9-27
Factor that affect the cooling rate of water
Aim: We want to find out the factors that the affect the cooling rate of water.
Hypothesis: If we put more water, it will cool down slower.
Variables:
Input variable: Amount of water
Output variable: Temperature of time
Control variables:
Control variable 1: Starting temperature
Control variable 2: Same container
Control variable 3: 100ml measuring cylinder
Control variable 4: The same thermometer
Materials:
• 500ml beaker
• Thermometer
• Gauze mat
• Tripod
• Bunsen Burner
• Water
• Stop watch
• Heatproof mat
• Retort stand
• Clamp
• Boss head
• Lighter
• Measuring cylinder

2. Diagram:
Method:
1. Set up equipment as shown in Diagram 1
2. Fill beaker with 200ml of water
3. Light the Bunsen burner
4. Wait for water to boil
5. Measure the temperature each minute for 5 minutes
6. Add 100mL of water for a total of 300mL
7. Heat the water to 100℃
8. Measure the temperature each minute for 5 minutes
9. Add 100mL of water for a total of 400mL
10. Boil the water
11. Measure the temperature each minute for 5 minutes
12. Turn off the Bunsen burner.

3. Results:
Conclusion:
Our hypothesis was correct, because for the first minute, the cooling rate was 4℃/
min; for second minute, the cooling rate was 3.2℃/ min; and for third minute, the cooling
rate was 2.6℃/min. It was because there will be more heat if there are more water. Also
in the same time, more heat will be cool down, so it will be slower than less water. Yes I
do trust my data, because I can see from that table, each time the temperature cools
slower than the one before it, and it is because we add 100mL more each time. So I’m
sure that our data is correct. And every time we looked at the degrees on the thermometer
very carefully.
Evaluation:

4. I think the errors in our experiment was that sometimes me and my group
members forgot to wear safety goggles when lighting the Bunsen burner, also during the
experiment. We are supposed to wear them during the whole experiment. And sometimes
we didn't pay a lot of tensions on the experiment, and we might miss the temperature of
that time, then our data will be wrong. Next time I need to concentrate on our experiment,
not talking with other people. And wear the safety equipments all the time. I don’t know
why we didn’t wear lab coat this time, but last year we wore lab coat for every
experiment. I think this experiment could be better by making the experiment in to a
competition, see which group can cools the water first. That might be more fun to do.