# Ib Physics Lab - Shc of Water

Topics: Temperature, Thermodynamics, Metal Pages: 5 (845 words) Published: February 18, 2012
Aim

To calculate the SHC of water
To see how accurately I can measure a known quantity

Research Question

Will the experiment carried out give us a good approximation of the SHC of water?

Hypothesis

The result we will get as the SHC of water will not be exactly the same as the literature value, but will be a very close figure to the literature value of the SHC of water as there will be some limitations to our experiment.

Variables

Independent: temperature of water
Dependent: SHC of water
Controlled: thermometer, iron block

Equation

M1C1ΔT = MCΔT + MCΔT

Apparatus

Water
Beaker
Calorimeter
Thermometer
Electronic scale
Bunsen Burner
Iron block
Tripod
Heatproof mat
Gauze

Method/Procedure

I first measured the mass of the iron block on an electronic scale •I then placed the block into a beaker of water, which I later placed on top of a Bunsen burner for it to boil •While I waited for the water to boil, I weighed and measured the initial temperature of the water inside the calorimeter •After the water boiled I quickly put the iron block into the calorimeter and started stirring the mixture until it reached thermal equilibrium •I finally measured the final temperature of the mixture

Raw Data

Mass
±0.005gSHC
(JKg-1K-1)TInitial
(oC)
TFinal
(oC)
Iron Block253.084.7x1029527
Water213.66?1927
Calorimeter152.163.85x1021927

Change in Temp.
(oC)

Iron Block68
Water8
Calorimeter8

N.B. I found that the SHC of the calorimeter is 3.85x102 by finding the SHC of copper, as the calorimeter was made of copper.

Data Processing

1st I’ll have to change the masses from grams into kilograms.

Iron Block – 0.25308 Kg
Water – 0.21366 Kg
Calorimeter – 0.15216 Kg

M1C1ΔT = MCΔT + MCΔT

0.25308 x 470 x 95-27 = (0.23166 x C x 27-19) + (0.15216 x 385 x 27-19) (There’ll be no need of changing the temperature units to Kelvin, as they have the same amount of divisions on their scales)

8088.4368 = 1.85328C + 453.78624
8088.4368-453.78624 = 1.85328C
7634.6544 = 1.85328C

7634.6544/1.85328 = 1.85328C/1.85328

C = 4119.536939 JKg-1K-1 ≈ 4119.54 JKg-1K-1= experimental value

Literature value = 4200 JKg-1K-1

Conclusion

The data collected and processed has shown to prove my hypothesis right. The result I will get as the SHC of water will not be exactly the same as the literature value, but will be a very close figure to the literature value of the SHC of water as there will be some limitations to our experiment. The experimental result I acquired was 4119.54 JKg-1K-1, lower than I expected, while the literature value is 4200 JKg-1K-1 this shows that the experiment was carried out correctly, but not perfectly. There is a 2% error in my result when compared to the literature value. The errors can be due to the fact that the experiment wasn’t orchestrated under professional conditions in a top-notch lab. Thus, one can without a doubt conclude by saying that the experiment faced some errors while it was being conducted, but still arrived at the area of the expected result.

Evaluation

The experiment was conducted well, despite the random and systematic errors that I came across. The main errors I identified were the following:

When transferring the iron block into the calorimeter some heat was lost to the surroundings as the block was out in the open.
The simple calorimeter we used was made from a copper can, and when the water and iron block were boiling the can was nearby, and since it’s a metal and metals are conductors of heat it possibly has gained heat from the Bunsen burner. Therefore, the temperature difference of the mixture, as a result, could have been made smaller by reason of heat being gained by the calorimeter.

The cover of the calorimeter wasn’t fully closed, leaving the water inside exposed and vulnerable to evaporation, which could lead to the loss of mass of the water and also cause...