Front Page- Physics Lab Report 4zv36

ADAMSON UNIVERSITY College of Science Physics Department Experiment No

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Specific Heat of Various Metals

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10:30-1:30 Thursday

Group No.

SCHEDULE

Grade

C.N.

NAME

COURSE

16 17 18 19 20

DIMACULANGAN, JAYVEE

ChE ChE ChE ChE ChE

D.O.P.

DIMAYUGA, KIMBERLY FRITZ FABIC, CAITLIN DOYLE FUNDANO, JEROME GAGUI, FARAH MAE

D.O.S.

Prof. Reggie C. Pantig Instructor

SIGNATURE

INTRODUCTION The experiment on the specific heat of various metal aims to: first, determine the specific heat of the given metals, specifically Aluminum, Brass, and Copper, using the experimental method. The results attained in the experiment will be compared to the standard value of the metals’ specific heat. Another of its objectives is to determine the relationship between the specific heat of the material and the change in the temperature; and, to identify the factors needed to change the temperature of the substance. Knowing the specific heat of a material can be handy in daily life. With the knowledge on specific heat, one can be able to calculate the exact amount of heat needed to change the temperature of a material to the desired amount; thus, energy can be conserved by avoiding application of excess that is unnecessary. Another importance of knowing the material’s heat capacity is on the design consideration of electronic circuit elements that are used everywhere. Most circuits are made using good conducting metals; so, by minding heat capacity and its relation on the change in temperature, one will know how much energy a material can handle to avoid overheating. One more of its importance is on climatology. Specific heat explains why coastal areas have moderate temperature all throughout the day which is due to the high specific heat of water, which is about ten times that of the land; therefore, the sea water heats up (and cool down) a lot slower than the land. Same explanation can be attributed to the extreme temperatures of the desserts which are composed of sands that have a low specific heat, and thus heat up and cool down rapidly as the temperature changes. Aside from these, specific heat also has applications to many other matters like adsorption, catalytic reactions, compositional analysis, corrosion/oxidation, crystallization, curing, decomposition reactions, differential scanning calorimetry, evaporation, glass transition temperature, magnetic transitions, mass changes, phase diagrams, phase transition temperatures, purity determination, reaction kinetics, residual mass, simultaneous thermal analysis, solid-gas reactions, solid-liquid reactions, solid-solid reactions, specific heat determination, sublimation, synthesis reactions, thermal stability, thermogravimetric analysis, and transition enthalpies.

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THEORY:

The quantity of heat Q required to change the temperature of a mass m of a material is proportional to the change in temperature

∆ T. The quantity of heat needed to change the temperature

also depends on the nature of a material described by its specific heat C. These relations can be expressed as follows:

Q=mC ∆T where: Q = quantity of heat absorbed or released, m = mass of substance,

C = specific heat,

Joules

kg

J Kg . K

∆ T = change in temperature , K The specific heat C of a substance refers to the amount of heat needed to raise the temperature of 1 g of a substance of a 1 degree Celsius. Law of Conservation of Energy states that energy cannot be created or destroyed but it can transform from one form to another. Making an energy balance of the system, we can have a mathematical model for the first law. Thus;

Heat lost by the system=Heat gained by the system

Percent error % is defined as the ratio of the experimental value to the standard value. It is used to measure the accuracy of a particular set of data.

Percent Error ( ) =

Experimental value x 100 Theoretical

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PROCEDURE: Firstly, measure the mass (m

sample

) of each metal samples which is aluminum, brass and copper.

For each metal sample, prepare the calorimeter with cold water about 10°C and then measure and record the mass of cold water (M cold water). Next, measure the initial temperature (T 1) of the cold water. Tie a thread to each of the metal samples and suspend into the beaker with water about 100 mL then start heating the water using electric stove to raise the temperature of water with the metal samples. The highest possible temperature corresponds to the initial temperature of the metals (T 2).When the samples attain the highest temperature (T 2), say the boiling point of water, get the aluminum sample from the beaker and immediately immerse into the calorimeter with cold water. Allow a small opening in the cover of the calorimeter to place the thermometer and use it to stir the water. Read and record the final temperature (Tf) which is the highest temperature attained by water as it comes to thermal equilibrium with metal sample. Calculate the specific heat of the metal samples using the Law of Conservation Energy (see Theory section). Assume also that the system is ideal such that no heat lost to surrounding. Repeat the procedure, now, using the metals, brass and copper. Record all the data gathered on Table 1.1.Ask your teacher for the true value of the specific heat of metals and complete the table. DISCUSSION OF DATA AND RESULT: Trial 1 Aluminum

Trial 2

Trial 3

Copper

Brass

msample , kg

0.0183

0.0521

0.0578

mcold water, kg

0.2491

0.2795

0.3222

T1, C (water)

9.9

9.6

9.6

T2, C (sample)

100.5

100.5

100.5

Tf1 , C

11.2

11.1

11.5

Csample, J/kg C

830.29

339.96

498.63

Ctrue value % Error

910 8.76

390 12.83

480 3.88

CALCULATIONS: 4

The results from the data table show that the mass has greatly affected the specific heat. Aluminum, being the lightest of them all, has the biggest value of specific heat. It takes 910 J/kg C to raise the temperature of one gram of Aluminum by one degree Celsius. And even though the metals have different mass, they still have almost close results of final temperature. ANALYSIS AND CONCLUSION: In this experiment we’re asked to determine the specific heat of the metals (Aluminum, Brass and Copper) experimentally, determine the relationship between the specific heat of the material and the change in temperature and lastly to identify the factors that affect the change in temperature that we can observed while conducting the experiment. During the experiment we first struggled in figuring out how to work the experiment correctly, we’ve done a lot of trials just to make sure that we’re doing the experiment accordingly. And during those trials we’ve encountered dozens of errors, External errors, Instrumental errors but mostly personal errors but we managed to cope with those errors and proceed to the experiment with minimal error. So after the experiment we observed that the Heat Capacity of the substance is the major factor that is responsible for the change in temperature. It is dependent upon the size and mass of the substance/sample. For example a sample containing twice the amount of another substance as another

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sample would require twice the amount of heat energy in order to achieve the same change in temperature as that required to change the temperature of the first sample.

REFERENCES:  

http://www.ebatco.com/specific_heat.html https://www.boundless.com/chemistry/textbooks/boundless-chemistry-

 

textbook/thermochemistry-6/calorimetry-60/specific-heat-and-heat-capacity-282-1442/ Miranda, Siguenza Re.,Siguenza Ru, College Physics 2 Laboratory Manual, 2011 Young and Freedman, University Physics(13th Edition)

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