The Specific Heat of a Metal

Purpose: In this chapter, we have been studying how the transfer of heat and energy from one substance to another alters the temperature of the objects. This lab will attempt to provide a real-world example of the theories put forth by the text. We will be heating several different substances and then submerging them in a set amount of water at standard conditions to see the change in temperature. Thus, we will hope to understand how to evaluate scientifically such temperature changes by means of heat flow.

Data and Calculations:

Measurements of Mass and Temperature
Mass of Copper	57.32g
Volume of Antifreeze	5mL
Density of Antifreeze	1.26g/mL
Mass of Unknown Metal	18.39g
Initial temperature1 of H2O in cup	22°C
Water1 with Copper @ 100°C	25°C
Water1 with Unknown @ 100°C in cup	26°C
Initial temperature2 of H2O in cup	21°C
Water2 with antifreeze @100° C in cup	28°C
Difference of temperature of Copper	3°C
Difference of temperature of Unknown	4°C
Difference of temperature of Antifreeze	7°C

Analysis:

1) Change in temperature of water for each substance: Copper=3°C Antifreeze=7°C Unknown=4°C.

2) Heat gained with Copper: q=∆H = 57.32 x 1 x (25-22) = 171.96
Heat gained with Anrifreeze: q = ∆H = (1.26x5)x1x(28-21)=44.1
Heat gained with Unknown: q = ∆H = 18.39x1x(26-22)=73.56

3) Specific heat of each substance:
Copper: C=171.96/(57.32x3)=.418
Antifreeze: C=44.1/((1.26x5)x7)=1
Unknown: C=73.56/(18.39x4)=1

4) N/A

5) See above.

6) Accepted value of copper: .387
Percent error=|.387-.418| = 8.01%
.387

7) It would be less than it actually is.

8) The substance may have had time to cool substantially while being transferred from the flask of boiling water to the styrofoam cup.

Results/Discussion: I have discovered that it is possible to measure the specific heat of substances if you only know their weight, and how much they changed the temperature of a certan amount of water under certain conditions. This allows me to understand clearly the origin of specific heat, and why it is used. The final specific heat of the unknown turned out to be a round 1. This is surprisingly high, and was probably an error in the experiment. I did not find any metal that was remotely close to this stellar specific heat capacity. My result for the copper, however, were satisfactorily close to the accepted value, which reassured me that at least part of the laboratory was completed successfully. I cannot say anything about the antifreeze, since I do not know what its accepted specific heat capacity is. Knowing that antifreeze is used to prevent the flow of heat, however, I think it is safe to assume that this substance would have a high specific heat capacity. Experimentally, we showed that it does indeed have a high specific heat capacity, also 1, which seems reasonable, though it is probably too low. Otherwise, car manufacturers would use water, which is cheaper and also has a specific heat capacity of 1, instead of the expensive and toxic antifreeze. I think some potential errors were that the unknown metal released too much heat as it was transferred from the double boiler to the styrofoam cup. This way, it seemed that it absorbed a lot less heat than it really did, and made its specific heat capacity a lot higher than it is in reality. I think this lab did a very good job of explaining specific heat. I now understand a lot better that specific heat capacity is directly related to how quickly a substance can be heated, or how much energy is needed to heat the substance. This will help my overall task of studying specific heat, because I have a better conceptual view of the topic in my mind.