An Investigation Into The Effect Of Surface Area on Volume Ratio
On The Rate Of Heat Loss
Heat loss from an object is affected by its surface area to volume
ratio (SA/V). The smaller the SA/V the faster heat is lost by
conduction, convection and radiation. Other factors may influence the
rate of heat loss by the above physical processes, e.g. insulation
type or thickness
Task
Prepare a detailed written plan for an investigation to determine the
effect of vessel size on the rate of heat loss. The investigations can
use the normal range of laboratory equipment and should take no more
than eighty minutes to complete.
Include:
· A concise, testable hypothesis, explained by an introduction.
· Full experimental details including control of the experimental
variables, and number of replicates.
· Risk assessment (scalds, cuts, electrocution, slipping, mercury in
thermometers).
· A table for the collection of raw results.
· An outline of how the results will be processed (table 2 and graph)
to determine whether the hypothesis should be accepted or rejected and
an assessment of error (range, standard error or semi-interquartile
range). A statistical test could be used, e.g. Mann-Whitney ‘u’ test
to compare the significance of a difference between two groups of data
(p = 0.05). See the statistics folder for this.
· Evaluation – discuss variability, trends, explanation involving
conduction, convection and radiation, improved methods and further
work.
Null Hypothesis
===============
Vessel size will not affect the rate of heat loss.
(For example, you could compare the rate of heat loss from 500 cm3 and
250cm3 conical flasks). You will need to be able to calculate the
surface area and volume of the vessels (at least approximately). Both
types of vessel will need to be plugged with cotton wool through which
a thermometer can be placed. Six replicates of each data set allow
the Mann-Whitney test to be done.
Variables include: volume; surface area; glass thickness and type;
First, 100 mL of regular deionized water was measured using a 100 mL graduated cylinder. This water was then poured into the styrofoam cup that will be used to gather the hot water later. The water level was then marked using a pen on the inside of the cup. The water was then dumped out, and the cup was dried. Next, 100 mL of regular deionized water was measured using a 100 mL graduated cylinder, and the fish tank thermometer was placed in the water. Once the temperature was stabilizing in the graduated cylinder, the marked styrofoam cup was filled to the mark with hot water. Quickly, the temperature of the regular water was recorded immediately before it was poured into the styrofoam cup. The regular/hot water was mixed for a couple seconds, and the fish tank thermometer was then submerged into the water. After approximately 30 seconds, the temperature of the mixture leveled out, and was recorded. This was repeated three
The data which was collected in Procedure A was able to produce a relatively straight line. Even though this did have few straying points, there was a positive correlation. This lab was able to support Newton’s Law of Heating and Cooling.
Planning Firstly here is a list of equipment I used. Boiling tubes Weighing scales Knife Paper towels 100% solution 0% solution (distilled water) measuring beakers potato chips Cork borer. We planned to start our experiment by doing some preliminary work. We planned to set up our experiment in the following way.
Variables --------- During the experiments, the water will be heated using different spirit burners containing different alcohols. I will be able to change different parts of the experiment. These are the. Volume of water heated:
Repeat using the SAME metal sample, but instead with the colder water. Do not record the temperature of the cold water in the calorimeter until immediately before adding the heated metal.
Then, repeat steps 7-11 another 4 times but with the room temperature water. For the room temperature water just leave it in the room but try not to change the room’s temperature. 15. Try to put all your recorded data into a table for organization 16. Repeat the entire experiment for more reliable data.
In a 100ml beaker 30mls of water was placed the temperature of the water was recorded. 1 teaspoon of Ammonium Nitrate was added to the water and stirred until dissolved. The temperature was then recorded again. This was to see the difference between the initial temperature and the final temperature.
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