Michael Thomas Harbuck
CHEM 2045C
12/11/2007

Specific Heat of a Metal

1.	 Specific Heat of a Metal Laboratory Formal Report

2.	 The purpose of this experiment is to learn the method for determining the specific heat of a metal.  The acquired information can then be used for identification as well as other energy equations.  As always, lab etiquette and safety take precedence and is practiced.  An introduction to the data analysis will using a computer is also a something new which will certainly is and will continue to be one of the best tools which the chemist can command at this time.  

3.	Procedure - Three pieces of an unknown metal sample, here number nine (#9), hereafter the analytical quantative processing begins.  The masses and volumes are determined and recorded using an analytical scale to four decimal places, and a graduated cylinder with single millimeter increments, respectively.  A styropor calorimeter is constructed and filled with a fresh eighty (80ml) milliliters of deionized water for each sample.  A hot plate is set up, and using a beaker, each of the pieces of the unknown metal are heated for a period of no less than fifteen (15 min) minutes.  Before the heated samples are placed into the calorimeter, the temperature of the water at the start of each analytical run must be measured and recorded.  The computer used is then brought online, calibrated, and the probe inserted into the calorimeter, BEFORE the heated sample is transferred into it.  As quickly as possible, the transfer from the boiling water to the calorimeter is accomplished using the large tongs provided.  The avoidance of heat loss into the surroundings is of utmost importance.  Stirring the water simultaneously will advance the heat transfer.  This is then repeated for each of the three samples.  At the end of each data recording of each sample, the graphic representation of the temperature change is printed.  

4.	Data and Calculations -  

The important factors and variable found are listed below.  

				
1.	Mass of the sample	57.2495g	27.2632g	30.0364g
2.	V-Initial H2O		71ml		66.3ml		66.0ml
3.	V-Final H2O		76.5ml		69.5ml		68.35ml
4.	V-H2O Calor.		80ml		80ml		80ml
5.	T-initial Calor.		21.78°	C	22.64° C	21.85°	C
6.	T-Final Calor.		26.28° C	24.92°	C	21.85°	C
7.	T-Initial Metal		101.0°	C	101.1°	C	101.0° C

Required Calculations:  

1.	ρ /Metal = mass/Volume	10.4090g/cm³	8.5198g/cm³	12.7814 g/cm³
2.	Mass of H2O/Calor.	80g		80g		80g
3.	ΔT-Metal			74.72°	C	76.08° C	76.71° C
4.	ΔT-Water Calor.		4.5° C		2.28° C	2.44° C
5.	Cp-Metal			.35179J/°C	.36758J/°C	.35412J/°C
6.	Cp-Average		.35783J/°C 			actual (.384524)
7.	Cp-% Error		6.94%	
8.	MM/Unknown Metal	73.919g	70.739g	73.429g
9.	MM-Average		72.699g			actual 63.55g
10.	MM- % Error		14.5%

11.	 Probable MM Error 
Without the inherent
Calculatory error of 8%	6.5%

5.	 Conclusion -  The specific heat lab is a fun lab, where new technologies for finding  the energy of transfers within a system are challenged.  The use of a computer to measure the change of the temperature in the calorimeter is a great help.  However, the amount of error due to the difficulty in obtaining quality and consistent readings is a large factor in the overall error in the experiment.  
The metal was readily identifiable from the color, even before the lab experiment began.  The measurements are all fairly precise EXCEPT for the graduated cylinder readings.  
Also, the equation which is used to derive the Molar Mass has an inherent error if 8 per cento, which when subtracted from the Molar Mass error of 14.5%, gives an error very close to that of the Cp calculations.  
The overall error of around 7% does not appear unreasonable for such an experiment.  

Mr. Michael Thomas Harbuck   November the 12th, 2007 Sanford, FL USA

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