Investigating Surfaces for Insulating Boiling Water in a Flask

873 Words2 Pages

Investigating Surfaces for Insulating Boiling Water in a Flask

Aim

I'm investigating which surface (matt black or silvery) is best at

insulating boiling water. I will investigate this by covering two

equally sized conical flasks in different materials; one in matt black

and one in silvery. After that I will fill each of the flasks with an

equal amount of boiling water. At regular intervals of 1 minute I will

measure the drop in water temperature in each flask.

Prediction

I predict that the flask with the silvery surface will take longer to

cool and overall there will be a smaller drop in temperature because

the silver surface will reflect nearly all heat radiation back into

the flask keeping the water warm whilst a dull black surface is a very

good emitter of heat radiation so a lot of heat will be lost to the

surroundings.

Method

======

Apparatus

---------

* Conical flasks

----------------

-One silver foil

-One matt black

* 2 Thermometers

* Cotton wool

* Stopwatch

* 400cm³ Boiling Water *

* Measuring jug

For the experiment, firstly get 2 equally sized conical flasks. Then

cover one of the flasks in matt black and one in silvery foil.

Secondly, boil 400cm³ (*possibly more as water can evaporate) of water

and put exactly 200cm³ in each flask. Then put a thermometer in each

of the conical flasks, and fill the top with cotton wool; this is to

insulate the flask thoroughly and stop water evaporating through the

top part of the flask. The thermometers have to be left to settle

before taking the first reading at zero minutes. After that at 1minute

intervals, read each thermometer and record the temperature. Repeat

this 3 times, so the test is fair and more precise. Afterwards, work

out the average for each reading. For Safety hand gloves should be

worn for handling hot water. Also make sure that the flasks containing

Open Document