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De la Salle University - Manila SPECIFIC HEAT OF SOLIDS (Using PASCO Scientific Equipment) Submitted by: Zophia Beatrice I. Nicolas ENGPHY12 EK2 INTRODUCTION Some people find it hard to differentiate temperature and heat. Temperature, in layman’s terms, is the measure of how hot or how cold something is. Common temperature units are degrees Celsius, degrees Fahrenheit, and Kelvin. On the other hand, heat is the amount of energy that is transferred due to diffe
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  De la Salle University - Manila SPECIFIC HEAT OF SOLIDS (Using PASCO Scientific Equipment) Submitted by: Zophia Beatrice I. Nicolas ENGPHY12 EK2 INTRODUCTION Some people find it hard to differentiate temperature and heat. Temperature, in layman’s terms, is the measure of how hot or how cold something is. Common temperature units are degrees Celsius, degrees Fahrenheit, and Kelvin. On the other hand, heat is the amount of energy that is transferred due to difference of temperature of two objects. According to the law of thermodynamics, heat transfer occurs from the object of high temperature to the one with a lower temperature. Thermal equilibrium is said to be achieved if both objects have the same temperature and not necessarily the same amount of heat. The SI unit of heat is joule (J) and calorie in CGS, which can be commonly seen in food products. Calorie is the amount of heat that is required to raise the temperature of one gram of water by 1 degree Celsius. Heat is the “ total kinetic energy of all molecules in a substance,” while temperature is the “ measure of average kinetic ene rgy of molecules in a substance” (Difference, n.d.).  Whenever commercial products are made, the materials that it will be composed of should be taken into consideration. An example of this instance is the use of cooking utensils. Cooking utensil should be able to transfer heat from the stove to the food it contains, while handles of spoons and forks should transfer heat to itself at a slower rate so that consumers would be able to use it. This ability of an object to resist heat transfer is called the specific heat capacity or commonly known as specific heat (c). “ Specific heat is the amount of heat required to raise the temperature of one gram of the substance by one degree Celsius. From the definition of the calorie, it can be seen that the specific heat of water is 1 cal/g-C ” (Specific Heat, n.d.).  The amount of heat of an object (Q) to be added or removed in order to reach a certain temperature can be obtained by multiplying the object’s mass with the specific heat of the material it is made out of and the change in temperature to be achieved or Q = (mass of object) (specific heat of the material) (change in temperature) The law of conservation of energy also applies in the transfer of heat. This means that the energy gained should be equal to the energy lost. In other terms, the amount of heat lost by an object should equal to the heat gained by the other. Q lost by water   = Q gained by sample  From the previous formula, (m water  )(c water  )(change in T of water) = (m sample )(c sample )(change in T of sample) By finding the mass of the water and sample, the change in temperatures of the water and sample, and with the given value of the specific heat of water (1 calories per gram-degree Celsius), the group will be able to find the approximate value of the specific heat of aluminum, lead and copper. METHODOLOGY All the methods indicated were very straightforward. First, fill the electric steam generator to about half way with water and heat the water. Next measure the weight of the empty and dry calorimeter (m cal ) and measure all the metal samples (m samples ): aluminum, copper, and lead. Attach threads to the metal samples. Record all the measurements. Then, fill the calorimeters half way with cold water. Record the mass of the water by subtracting mass of the calorimeter from the mass of the calorimeter with water. Record the initial temperature of the cold water and the temperature of the boiling water. Suspend the metal samples in the boiling water for 2 minutes. After 2 minutes, immediately wipe the metal samples and suspend it in the calorimeter. Slowly stir and record the highest temperature recorded. Our group first weighed out the calorimeters to be used in our experiment and obtained eleven grams. After this, we weighed the metal samples to be used which are aluminum, copper and lead with masses of 203g, 195g and 236g respectively. Then, our group filled our calorimeters with water until it was half full and added the metals with it one by one. With the formula below, we are able to calculate for the mass of the water inside the calorimeter. m water   = m total    –   (m cal  + m sample ) We used a thermometer on the water inside the calorimeter and we got 14.1 degrees Celsius, 13.2 degrees Celsius and 10.5 degrees Celsius. We boiled water using a heater until its temperature reached one hundred five degrees Celsius and dumped the metal into the water for some time. Then, our group submerged in quickly into the calorimeter. For each calorimeter of each metal, we observed 28.5 Celsius, 21 degrees Celsius and 13.8 degrees Celsius respectively. Having this, we calculated for the temperate change of the water being twelve degrees Celsius, seven degrees Celsius and three degrees Celsius respectively. Change in T water   = T final  - T cold  Change in T sample  = 100 degrees C - T final     RESULTS AND DISCUSSION Table 1.1 Results obtained from experiment last July 28, 2014 Material of metal sample Aluminum Copper Lead Mass of calorimeter, m cal (g) 18 18 18 Mass of metal sample, m sample  (g) 203 195 236 Mass of calorimeter, water, and metal sample, m total  (g) - - - Mass of water, m water   (g) 212 190 208 Temperature of boiling water in the heater, Tboiling water (oC) 100 100 100 Temperature of water, T cold  ( o C) 14.1 13.2 10.5 Equilibrium temperature of water and metal sample, T final  ( o C) 28.5 21 13.8 Temperature change of water, ∆T water   (C o ) 14.4 7.8 3.3 Temperature change of sample, ∆ Tsample (Co) 71.5 79 86.2 Specific heat of water, c water   (cal/gC o ) 1 1 1 Calculated Specific Heat, c s  (cal/gC o ) (use equation 3) 0.205 0.096 0.034 Standard Value of Specific Heat (cal/gC o ) (see Table of Physical Constants) 0.210 0.092 0.038 Percentage error 2.38% 4.35% 10.53% Table 1.1 shows the data that we were able to obtain from the experiment. Knowing that the specific heat of water is 1 J/gC, we calculated for the specific heat of each metal sample  being 0.205 J/gC, 0.0906 J/gC and 0.034 J/gC for aluminum, copper and lead respectively. Our  group then looked for the actual specific heat values of the metals in the appendix given provided  by the De la Salle University Physics Department and found out they are 0.210 J/gC, 0.092 J/gC, and 0.038 J/gC. We calculated the percentage difference errors of each and found out they are 2.38%, 4.35% and 10.53%. There are many reasons as to why we obtained those values of percentage error. One of them is the continuous transfer of heat in the system or in our classroom. The calorimeter where the cold water was contained is not a closed system. The same thing can be said to the electric steam generator. There is also a chance of making errors in weighing the calorimeter, metals, and the water. CONCLUSION In conclusion, we can say that our experiment was somewhat successful except for the huge percentage error of the specific heat of lead, which was 10.53%. The others have  percentage errors that are less than 5% and are acceptable. The possible reasons for these errors have been explained in the previous chapter. In ending this report, there are some recommendations in the experiment that are group noticed. We could lessen the error by improving our calorimeter’s ability to contain the heat of the water inside it. We can place a cover on top so as to prevent the heat transfer between the water and the atmosphere. Errors are unavoidable in all experiments; however, measures should be taken to lessen them as possible. Also, by doing this experiment, I now finally understand that the constants given to us did not  just appear out of nowhere. They were obtained using these formulas using values that were  produced from careful experiments. REFERENCES: Difference between heat and temperature (n.d.). Retrieved on August 25, 2014 from http://physics-sunil.blogspot.com/2012/05/difference-between-heat-and-temperature.html Specific heat of solids [PDF document]. Retrieved from Physics Department Experiments Web site: http://www.dlsu.edu.ph/academics/colleges/cos/physics/_pdf/cos-specific-heat-of- solids.pdf

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