Specific Heat of Various MetalsLee Flores, John Mark Garcia, Richard Ivan Garcia, Novelyn Glino, Ryan Christian Jacinto , Jose

Angelson Lazo, Ronel Liao and Anna Dominique ManlagñitGroup no.3

Physics Department, Adamson University, Ermita, Manila

AbstractThe experiment focuses on how to determine the specific heat of the three metals and also to

verify the relationship between the specific heat of these metals provided and the change in temperature. The specific heat was found to be the amount of heat per unit mass required to raise the temperature by one degree Celsius. In this experiment, the metal samples were heated in boiled water and recorded the temperature of the water after the equilibrium was achieved; then it was added and stirred to a calorimeter with cold water, the highest temperature was recorded at equilibrium temperature. The experiment proved that different materials have different specific heat and the change in temperature is directly proportional to the magnitude of heat.

1. Introduction

Heat and temperature are somehow alike but in physics they are distinct to each other. Heat is caused by a temperature change that leads to energy transfer while temperature is the measure of how hot or cold an object is. The specific heat C is the measurable quantity of heat energy to change the temperature of a specific object or material. The thermal equilibrium can be achieved when the materials permit to interact and able to reach a point where in its temperature is no longer changing or it is in the steady state. The purpose of this experiment is to determine the specific heat of metals experimentally and compare the results to its true value. Also, it aims to verify the relationship of the change in temperature to the specific heat of the materials. Lastly, to find out the factors needed to change the temperature of substances.

2. Theory

Q is the quantity of heat required to change the temperature of an object given a mass m and it is proportional to the change in temperature. The Q or the quantity of heat also depends on the composition of the material because different material has its own specific

heat, thus specific heat C of a material is the amount of heat needed to raise the temperature of one gram of the material by one degree Celsius. These relations can best described by this equation. Q=mC∆T (1)

Where Q is the quantity of heat absorbed of released by the object in Joules; m is the mass of the substance in kilogram; C is the specific heat of the material the object is composed of in Joules per kilogram Celsius

degree; and T is the change in temperature expressed in Celsius degree.

Objects that interact with different temperature can come into thermal equilibrium by either losing or gaining heat until there is no more change in the interacting objects temperature.

3. Methodology

In this experiment, the following materials were used; calorimeter, aluminum, brass, and copper metal, thread, thermometer, triple beam balance, beaker, electric thermos as the heating instrument, and cold water. The group weighed the cold water and the metals

first and the thread was tied to the metals so the group can easily transfer them after soaking the metals inside the beaker with hot water from the electric thermos. After the equilibrium temperature was reached by the metal and the hot water, the temperature was recorded using the thermometer then it was transferred inside the calorimeter with the cold water. The highest temperature attained by the water as it reached the equilibrium was recorded using again the thermometer. Then the specific heat of the metal was calculated.

4. Results and Discussion

The measured data for mass and temperature for the specific heat of the samples were recorded in the table along with the results of the computations.

Table1 shows the masses of different metals, initial and final temperatures, and specific heat capacity for experimental and true values.

Table1. Specific Heat of MetalsTrial 1Aluminum

Trial 2Copper

Trial 3Brass

msample, kg 0.018 0.058 0.052Mcold water, kg 0.041 0.043 0.047T1, 0C (water)

10.5 13.4 8.00

T2, 0C (sample)

79.5 81.6 78.7

Tf, 0C 15.6 19.9 14.6Csample,J/kg Co

761 327 389

Ctrue value 910 390 480%error 16.4 16.3 18.9

As shown in table 1, the metal samples

in the experiment had different masses with different computed heat capacities. Trial 1 and

2 showed that as the mass increases, the heat capacity of the metals decreases, but it was another case for trial 3 but it could be attributed to higher percentage error. This could mean that the specific heat capacity of a metal was inversely proportional to its mass. Based from the results it was evident that the change in temperature for trial 1 has the highest magnitude compared to trial 2 and 3, this could mean that the change in temperature is proportional to the magnitude of heat.

The errors that the group committed could be attributed to the absence of an isolated system to do the experiment since the surroundings keeps on absorbing heat from the system thus making our change in temperatures to be not accurate.

5. Conclusion

In the experiment the group learned that different materials like aluminum, brass and copper have different specific heat. The group computed for the experimental value for their respective specific heat and compared them with the true value where the group acquired an acceptable percentage error. Based from the data acquired the group observed that specific heat and change in temperature are inversely proportional to each other. Lastly the group determined that mass and specific heat are the factors that are needed to change the temperature of an object, and each material has its own specific heat.

References:

1. Physics Committee, College Physics 2 Laboratory Manual, 2011, Adamson University, Manila.