Introduction:

The rate at which an object cools (i.e. how quickly its temperature decreases) depends upon several factors, including:

• Surface area
• Volume
• Type of insulation
• Temperature difference with the surroundings

For this investigation, the effect of the temperature of water upon the rate of cooling will be investigated. The temperature-drop over 5 minutes (600 seconds) will be measured for 200ml of water at different start temperatures. The average rate of cooling can then be found by:

Apparatus:

• digital stopwatch
• 250ml beaker
• rubber bung
• thermometer
• bunsen burner
• tripod
• gauze
• retort stand and clamp
• goggles

Control Variables:

• Volume of water used: 150ml
• Size of beaker (i.e. constant surface area): 250ml
• Time interval of cooling: 5.0 minutes (600 seconds)
• Temperature of the room: 21°C

Method:

• Fill an empty beaker with exactly 150ml of water (check side-scale of the beaker)
• Set up apparatus as shown above. Ensure the thermometer is about 2cm above the bottom of the beaker.
• Light the bunsen burner and put on a blue flame. Heat up the water.
• When the temperature on the thermometer has reached 90°C, immediately switch off the burner.
• Start the stopwatch and time for 5.0 minutes.
• Read the thermometer value at the 5.0 minute mark.
• Before repeating the experiment, check the level of water is still 150ml (some may have evaporated) and add more water if required.
• For different start temperatures, repeat steps 3-7 but turn off the burner at the desired temperature.

Results:

Conclusion:

There is a strong correlation between the average rate of cooling and the start temperature: the greater the start temperature, the faster the average rate of cooling.

Inline Feedbacks
Mike
1 year ago

It’s confusing to express the cooling rate x 1000? Better to record degrees C cooling per minute.

Ash
2 years ago

Thank you this has been very helpful

Holo
2 years ago

Why does it cool the most in the first five mins

fawziya A.
4 years ago

very good

Pri
4 years ago

You have made an error with the time. 5 min is 300s, not 600.

student
5 years ago

5 mins is not 600 seconds

Angie
5 years ago

How 5 minutes can be 600 sec ? I think it is 300 sec therefore the average rate of cooling is wrong.

Henry P.
5 years ago

Perfect, thanks

brian
5 years ago

guest
5 years ago

risk assessment?

Georgia
5 years ago

This is the best link EVER!!!!!!!!!

guest
5 years ago

this was a real nice bit of work gotta love it

guest
6 years ago

lovely stuff

jack
6 years ago

Alisha M.
5 years ago

Guest
6 years ago

hi, nice work! Useful for the CAU

callum E
6 years ago

amazing wow its so good I cant believe it

S.Henry
6 years ago

thanks

Nikesh C.
6 years ago

Stella