Name: ASHWIN BHAKRE

Partners: ASHWIN, ALEX DAUGHTRY

Date of experiment: 24th and 29th September 2010

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Aim: We are trying to find out if water takes longer time to cool down if the starting temperatures are different.

Hypothesis: I think the hotter the water is, the lesser it will cool down in 10 minutes.

Variables:

Input variable: The starting temperature of the water is our groups input variable. We shall change it by keeping the measured amount of water on the flame for a longer period of time.

Output variable: Our output variable is the time the water takes to cool down. We shall measure it by using stopwatches.

Control variables:

Control variable 1: Our first control variable is the amount of water we are going to use. I plan to keep it constant by using a graduated cylinder to measure it out.

(What’s the temperature of the water? You should give more details)

Control variable 2: Our second control variable is the room temperature. I plan to keep it constant by keeping an eye on the A/C remote.

Control variable 3: Our third control variable is the beaker we are going to use. I plan to keep this one constant by using the same beaker.(How big is the beaker? You have to give a specific number )

Control variable 4: Our fourth control variable is the thermometer we are going to use. I plan to keep this one constant by using the same (red oil) thermometer every time so that there are no errors.

Control variable 5: Our fifth control variable is the cooling time. We plan to keep this the same by using a stopwatch to measure out 10 minutes exactly.

Materials:

Bunsen Burner Gauze mat Tripod Retort stand Boss head 250 ml beaker Graduated cylinder (100ml)

Thermometer (red oil) Lighter Safety glasses/Apron Metal tongs Water( how much?) Bunsen Burner Mat

SORRY NO DIAGRAM !

Method:

1. Set up equipment and put on safety equipment.2. Measure out exactly 100ml of water in a graduated

cylinder and pour it into the beaker.3. Place the beaker (250 ml)on top of the Bunsen burner

and with the thermometer inside.4. Turn the Bunsen burner on and wait till the designated

temperature of the water is reached.5. Using the metal tongs pick up the beaker and place it

onto the Bunsen burner mat and start the stopwatch.6. Observe the temperature drop for 10 minutes and

record data into your book for every minute.7. Repeat the process with the 2 different starting temperatures of the water.

Results:

TIME IN MINUTES

STARTING TEMP. AT 60 ˚C

STARTING TEMP. AT 70˚C

STARTING TEMP. AT 80˚C

1 minute 58˚C 70˚C 80˚C2 minute 57˚C 69˚C 75˚C3 minute 57˚C 67˚C 71˚C

4 minute 56˚C 64˚C 67˚C5 minute 56˚C 61˚C 64˚C6 minute 54˚C 59˚C 63˚C7 minute 53˚C 57˚C 59˚C8 minute 52˚C 55˚C 57˚C9 minute 50˚C 54˚C 55˚C10 minute 50˚C 53˚C 53˚CTOTAL TEMPERATURE DROP

10˚C in 10 minutes

17˚C in 10 minutes

27˚C in 10 minutes

Conclusion:

My hypothesis was proved wrong because our results clearly showed that in 10 minutes time the 60˚C water dropped only 10˚C while the 70˚C water dropped 13˚C and 80˚C water dropped a whooping 23˚C. There was one factor that I think must have affected the experiment the

most. This experiment was conducted in two different lessons so in the first lesson after I had heated the water up to 60˚C I had just let it stay on the gauze mat and cool. But on the other lesson for the other two tests I had taken the beaker off the gauze mat and put it on the Bunsen burner mat. I think because of leaving the beaker on the gauze mat the water did not cool down as much as the others because the gauze mat must have been hot too which might have made the cooling down process slower.

Evaluation:

I think my experiment gave accurate results from the second two tests but the first one kind of spoiled it but it still proved my hypothesis wrong so I would call this a successful experiment because there is something that always goes wrong in experiments and we should learn from that mistake. I sure have learnt something from it, which is that you should always do the same thing in an experiment because if you don’t it can change the whole results by a mile. Next time I do this experiment I would try to make my measurements more accurate and keep things constant for each test. I think this experiment was a good one because I learnt something from it.

Good report, it is very specific, but it would be better if you have more details.