Lab Report: Specific Heat
explanatory Essay
379 words
Introduction The porpoise of these is to determine the Specific Heat. Also known as Heat Capacity, the specific heat is the amount of the Heat Per Unit mass required to raise the temperature by one degree Celsius. The relationship between heat and temperature changed is usually expected in the form shown. The relationship does not apply if a phase change is encountered because the heat added or removed during a phase change does not change the temperature. Q = cn^T The molar specific heats of most solids at room temperature and above are nearly constant, in agreement with the Law of Dulong and Petit. At lower temperatures the specific heats drop as quantum processes become significant. The Einstein-Debye model of specific heat describes the low temperature behavior. The metal samples are: · Copper (CU) · Aluminum (Al) · Zinc (ZN) · Tin (Sn) · Lead (Pb) · Steal/iron (Fe) · Brass (an alloy of Zn and Cu) PROCEDURE: 1. In a Styrofoam cup, record the temperature of the 200 ml of cold water. This is 200 g of water, as the density of water is 1 g/ml. 2. Obtain a sample of metal that has been immersed in boiling water and place it in the cup of water. 3. Wait until the temperature no longer rises (thermal equilibrium), and record the temperature increase. 4. Discard the water and measure the mass of the metal. 5. Repeat the above for each metal. CALCULATIONS: 1. H=mc^T=(200g/1)(1cal/goc)(2oc/a)=400cal C=H/m^T=400cal/(128g)(20c)=1.5625cal/goc 2. H=mc^T=(200g/1)(1cal/goc)(2oc/1)=400cal C=H/m^T=400cal/(20.1g)(2oc)=400cal/40.2 goc=9.95cal/ goc 3. H=mc^T=(200g/1)(1cal/goc)(2oc/1)=400cal C=H/m^T=400cal/(53.9g)(20c)=37.38cal/ goc 4. H=mc^T=(200g/1)(1cal/goc)(2oc/1)=400cal C=H/m^T=400cal/(65.3g)(20c)=3.06 cal/ goc 5. H=mc^T=(200g/1)(1cal/goc)(2oc/1)=400cal C=H/m^T=400cal/(70.5)(20c)=400cal/141goc=2.83 cal/ goc 6. H=mc^T=(200g/1)(1cal/goc)(2oc/1)=400cal C=H/m^T=400cal/(70.1g)( 20c)= 2.83 cal/ goc 7. H=mc^T=(200g/1)(1cal/goc)(2oc/1)=400cal C=H/m^T=400cal/(50g)(20c)=4 cal/goc RESULTS: Type of Metal Experimental © of Metal Actual © of Metal CU 400cal 1.5625cal/goc Al 400cal 9.95cal/ goc ZN 400cal 37.38cal/ goc Sn 400cal 3.06 cal/ goc Pb 400cal 2.83 cal/ goc Fe 400cal 2.83 cal/ goc Brass 400cal 4 cal/goc
In this essay, the author
- Explains that the porpoise of these is to determine the specific heat, also known as heat capacity, which is the amount of heat per unit mass required to raise the temperature by one degree celsius.
- Explains the molar specific heats of most solids at room temperature and above are nearly constant, in agreement with the law of dulong and petit.
- Explains that in a styrofoam cup, record the temperature of the 200 ml of cold water.
- Describes how to obtain a sample of metal that has been immersed in boiling water and place it in the cup of water.
- Explains that different metals have different specific heats, because they had different densities and there were different mass of them. the most different calculated was for copper (cu).
Related
- explanatory
- opinion
- comparative
- analytical
- Heat Capacity of An Unknown Metalexplanatory essayThe purpose of performing this lab was to find the specific heat capacity of an unknown metal.
In this essay, the author
- Explains that the purpose of performing this lab was to find the specific heat capacity of an unknown metal.
- Describes how a hot plate is acquired, plugged in, and if left to warm up, fill two beakers with 0.075kg of water and record the temperature.
- Explains how to test a hot plate, two beakers with 0.075kg of water, select metal objects, and record the starting temperature of the water.
- Explains that the temperature increase wasn't great when the object was inserted into the second beaker because of the time restrictions put onto our experiment.
- Explains the lab propertiesitemweightstartingtemptemp of metal in cold watertemp changechain10g100 c24 degrees c23 degrees
- Describes the c=(945) / (3.367) (c=280.6object) and the chain: (0.075*4200*1), (0.01*76), (315) and (0.76) (414.5object).
- Explains that each metal has a different thermal conductivity which is the metal's ability to conduct and hold heat.
- Explains metal objects and suspected metal make ups: bolt: c=(0.075*4200*3) / (0.0455 * 74) copper:
- Concludes that their hypothesis was correct. a metals heat capacity is determined by the makeup and density of a metal.
1176 wordsRead More - Energy Conservation Labexplanatory essayThe purpose of this experiment is to try to find the original temperature of the hot water in the heater using the 60 degrees C thermometer. Use your 60°C thermometer, and any materials available in your laboratory, to determine the temperature of the water in the coffee pot. During this experiment we calculated the original temperature of a heater after it had been cooled down, and we did this by measuring hot, cold, and warm water, with a thermometer that had tape covering 60 degrees and up. When preformed each of these experiments with each temperature of water, plugging them into the equation (Delta)(Ti – hot – Tf) T Hot x Cp x Mass(Cold) = (Delta)(Tf – Ti – Cold) T Cold x Cp x Mass(Hot)(d
In this essay, the author
- Explains how they calculated the original temperature of a heater by measuring hot, cold, and warm water, with tape covering 60 degrees and up. the lab gave them the skills to work well in the professional environment and to be conscious of the environment.
- Explains lab 5's 'molecular model building' experiment. the handout provided charts for us to record data on the number of valance electrons present in a molecule.
- Explains the purpose of lab 6: to determine the amount of heat liberated by a particular fuel by measuring the increase of the water temperature earner provided by the fuel.
- Describes how the first week of the experiment was a collaboration of ideas and planning that helped develop skills in leadership and problem solving.
- Explains the main purpose of the experiment, which was aimed at comparing authentic and sample ions.
- Explains the formulas used to measure the amount of different ions in a fertilizer sample by counting to preform tests. the begging of the experiment requested that the percentage of so4 be found.
- Describes how the energy content of fuels experiment focused mainly on the amount of heat liberated by a particular fuel contained in alcohol lamps, which stored absolute ethanol, butanol or kerosene.
1207 wordsRead More - Calorimetry Lab Reportexplanatory essayThe purpose of the lab is to understand how to calculate the calorimeter constant by using a calorimeter. This allows us to analyze the heat reaction of different substances. Calorimetry is a word that comes from both Latin and Greek. The prefix “Calor” in Latin signifies heat and the suffix “metry” in Greek means measuring. Therefore the word itself translates to measuring heat. Joseph Black, was the first scientist to recognize the difference between heat and temperature. Energy is always present in chemical and physical changes. The change of energy that occurs when there is a chemical change at constant pressure is called enthalpy. Enthalpy changes , as well as physical and chemical changes, can be measured by a calorimeter. The energy that is released or absorbed by the reaction can be either absorbed or released by the insulating walls of the instrument.
In this essay, the author
- Explains that the lab's purpose is to understand how to calculate the calorimeter constant by using the instrument. calorimetry is a word that comes from both latin and greek.
- Explains that styrofoam cups act as calorimeters due to their insulating properties. since most of the heat that forms is absorbed by the solvent, the temperature can be altered.
- Explains that when the amount of hot water released and cold water absorbed does not coincide, it means the calorimeter is absorbing some of the heat.
- Explains the hess's law, which states that the enthalpy of a reaction is independent of the steps it takes to go from reactant to product.
433 wordsRead More - Thermometer Lab Reportexplanatory essayTo calibrate the thermometer that I bought from Irvine Valley College, I followed the steps given by my Astronomy 20 teacher, Roy McCord. First, I purchased distilled water. I then found a reliable source, to research the point at which water freezes and boils in Celsius. Water freezes at 0°C and boils at 100°C.
In this essay, the author
- Explains that to calibrate the thermometer, they followed the steps given by their astronomy 20 teacher, roy mccord. they purchased distilled water and researched the point at which water freezes and boils in celsius.
- Explains how they took the distilled frozen water and the calibrated thermometer and recorded the temperature. they repeated the process two more times.
- Explains how they tested their thermometer in boiling water. the source stated that water boils at 100°c, so this was what they were expecting.
- Explains that they made a chart to record how their thermometer measured freezing and boiling water, and proceeded to find the average.
- Explains that their thermometer was slightly inaccurate due to their measurements. nothing is exact or perfect, but it is very close to accurate, being off in between 0.1-1°.
401 wordsRead More - During the experiment I will be taking a number of measurements, I will firstly take the initial temperature of the water and initial mass of the alcohol I will then burn the alcohol until an increase in temperature of 20oc has occurred in the water I will then reweigh the alcohol.
In this essay, the author
- Explains that they will investigate the difference in enthalpy of combustion for a number of alcohols.
- Explains that they plan to measure the enthalpy change by burning alcohol, using a spirit burner, and then use the heat produced during the combustion of the alcohol to heat 100ml of water.
- Explains that during the experiment, they will take a number of measurements, such as the initial temperature of the water and initial mass of alcohol. they will then burn the alcohol until an increase in temperature has occurred.
- Explains that they will need to repeat their experiment a number of times and take an average so they are sure of an accurate result.
- Explains that the calorimeter is held directly above the spirit burner by a retort stand and clamp, and the mercury thermometer, which is very accurate, will be used to measure the water temperature.
- Predicts that alcohols with a greater number of carbon atoms within the molecule will have higher enthalpy of combustion than those with less. bond breaking requires energy while bond making releases energy.
- Explains the balanced equation for the combustion of methanol. the type and number of bonds within each mole of reactants and products are shown.
- Explains that the total energy required to break the bonds in the reactants is 2807.5 dh/kj mol-1, and the difference between them and products is 524.5
- Explains that the energy released by the alcohol is only an approximation for the combustion of methanol because the bond enthalpies vary slightly from one molecule to another.
- Describes the alcohols that they plan to use in their investigation, including methanol, ethanol and propanol.
- Explains that methanol ch3ho + 1.5o2 (g) co2 + 2h2o (l)3 c__h 413 1,5o=o 497
- Explains that the bond enthalpies worked out above clearly show an increase in the overall energy that is released as the alcohols increased in size.
- Compares the enthalpy of combustion (dhc) of different alcohols.
- Explains that they are going to use propan-1-ol and butan-l as representatives of the two alcohols. they are large enough molecules to form isomers and have the closest structural arrangement.
- Explains that they need to use alcohols with as similar structure as possible, with the only difference being the number of carbon atoms within the molecule.
- Explains that alcohols are flammable, so they need to be handled with care, avoiding spillages, and kept in a suitable container.
- Explains that their experiment is safe as long as it is carried out sensibly taking heed of the general laboratory rules.
- Explains that alcohol initial temperature +/- (oc) finaltemperature (g) methanol 21 43 22 213.18 212.06 1.1221
- Explains that the bottom of the calorimeter had a black sooty type substance on it, which was affecting their results for butan-1-ol.
- Explains that the smaller alcohol's needed less energy to break the bonds in the reactants and so more energy is needed to initiate the reaction.
- Explains that carbon is a better insulator than copper, as it has lower thermal conductivity value and stops heat getting through to heat the water as there should be.
- Explains that their results show a clear increase in the energy released per unit mass of alcohol. they need to find which alcohol releases the most energy per mole.
- Explains that energy mass x temp increase depends on the substance you are heating, it is called the specific heat capacity.
- Explains that the mass of water heated, 100g, is the heat energy exchanged during the experiment, which needs to be converted to heat taken in per mole of alcohol burned.
- Explains that the heat absorbed by the calorimeter can be worked out.
- Explains that the two values worked out above for the energy absorbed by the water and the calorimeter give the total.
- Explains the average enthalpy of combustion for the alcohols in the table.
- Compares their results to the bond enthalpy values that they had worked out earlier.
- Explains that it is possible to measure the exact enthalpy of combustion using a bomb calorimeter apparatus. heat losses can be eliminated if the thermo chemical investigation is coupled with an electrical calibration.
- Compares the values of the enthalpy of combustion given by the bomb calorimeter to their results.
- Explains that methanol was the least accurate at 38.9% of what it should have been and propon-1-ol at 49.5%.
- Opines that their results have been consistently accurate, with the gap between the most accurate and the least accurate being only 10%. this gives them the impression that they are not just wrong because of human error.
- Explains that the enthalpy's of combustion that they are comparing their results to were measured under different conditions so this means they would be different any way.
- Explains that heat produced in the experiment was aloud to escape before it had even entered the apparatus and even heat that got into the water could escape back out of the calorimeter.
- Explains that they redid the experiments now using the insulation material, attaching it to the sides of the calorimeter. the results were an improvement on the previous attempt.
- Explains that their results show a clear increase of around 9% although this does vary from alcohol to alcohol. the heat produced does not even enter the apparatus, it is aloud to escape immediately.
- Opines that the accuracy of their experiment could have been improved by using a bomb calorimeter, which was not available to them.
- Compares the enthalpy of combustion from the bomb calorimeter to the results that they got from their experiments. the only thing that could have been improved was to measure all the heat energy that had been released by the combustion of the alcohols.
- Opines that lining the reflector with silver/ shiny surface would keep more of the heat produced during combustion close to the calorimeter so more is absorbed.
- Opines that there are other aspects of the enthalpy of combustion of alcohols that they could have investigated.
3890 wordsRead More - Density Labcomparative essayIt was concluded in this lab that the metal cylinder was Iron and the metal plate was Aluminum. Looking at a chart of densities and using the results to verify, concluded this. The percent error was low for most objects except the metal plate. Next time measuring should be done more carefully. However this could have been caused by human error or imprecise equipment. The density of water at 23°c should be approximately .9975g/ml. This measurement was found in a chart, along with the other densities used to find the percent error. The process of finding density was successfully completed without any problems. The procedure and calculations went smoothly and overall this lab was successful.
In this essay, the author
- Explains the objective of this lab was to calculate the densities of various objects using different techniques.
- Explains that the mass of the 100-ml. graduated cylinder was measured without water but with the rubber stopper.
- Explains that water was placed in the 100-ml. graduated cylinder without the metal or rubber stopper.
- Explains the theory of water of displacement: a volume of water was measured when the metal cylinder was added. the initial volume was subtracted from the second (total) volume.
- Explains that the density calculated was sensible because it was less than 1, meaning it would float on water.
- Concludes that the metal cylinder was iron and the aluminum plate was aluminum. the percent error was low for most objects, but could be caused by human error or imprecise equipment.
684 wordsRead More - Phase Change Lab Reportanalytical essayTitle: Observing what temperature the water must be at the undergo a phase change Introduction: A phase change is a result from the kinetic energy (heat) either decreasing or increasing to change the state of matter (i.e. water, liquid, or gas.) Thus saying, freezing is the phase change from a liquid to a solid which results from less kinetic energy/heat. Also, melting is the phase change from a solid to a liquid which results from adding kinetic energy/heat. So, the freezing and melting point of something is the temperature at which these phase changes occur.
In this essay, the author
- Explains that a phase change occurs when the kinetic energy decreases or increases to change the state of matter. the freezing and melting point of something is the temperature at which these phase changes occur.
- Describes how a plastic cup was filled half way with crushed ice and mixed with 4 spoonfuls of 5 ml of sodium chloride. a thermometer was placed inside the cup to take the temperature and the result was recorded on an observation sheet.
- Describes the temperature of the frozen water table, the ice bath temperature, and the written observations.
- Analyzes the temperature of the water in the vial and the ice/salt mixture every 3 minutes over a period of 30 minutes.
- Explains that the lab's main findings are that water will freeze at 0 degrees celsius. this can be proven directly from the graph and the table.
704 wordsRead More - Glassware Experimentexplanatory essayAfter finishing the trials, our group subtracted the mass of the glassware without water from the mass of the glassware with water in order to find the mass of the water in grams. Then, we divided the mass of the water by the density(g/cm^3) of the water in order to find the volume (mL). An example calculation from the 5.00mL pipet is: (4.9285mL+4.8839mL+4.9367mL+4.9265mL+4.9134mL)/5 = 4.9178. In most cases, the temperature of the water was around 23 degrees celsius, making the density about .998408 g/cm^3 for many of the trials. The densities we used were found online. The next calculations we performed were to determine the average volume of the water in each person’s five trials by adding up all of the volumes(mL) and dividing that number by five. Using the average volume, we then calculated the
In this essay, the author
- Explains that the primary goal of the experiment was to determine which types of glassware are the most accurate and precise in measuring substances.
- Explains how the group divided the mass of the water by the density (g/cm3) to find the volume (ml). the percent error allows them to determine which glassware is the most accurate at measuring substances.
- Explains that the graduated cylinder had a percent error of 1.6400%, and the beaker and erlenmeyer flask had higher percent errors.
- Explains that they learned the different steps required for completing an experiment, and how to handle lab equipment properly.
874 wordsRead More - Viscosity Essaycomparative essayThe thermometer, containers, and iron ball were secured of any possible contaminants. The stopwatch was calibrated and checked to be correctly measuring the time in seconds and milliseconds, by comparison with other stopwatches. The thermometer was checked to be accurately measuring the temperature of lukewarm water, and was al...
In this essay, the author
- Explains the viscosity of corn syrup, measured in seconds it takes for an iron ball to move downwards in the fluid.
- Explains that the thermometer, containers, and iron ball were secured of any possible contaminants. the stopwatch was calibrated and checked to be accurately measuring the time in seconds and milliseconds.
- Recommends placing the graduated cylinder in one of the beakers, and waiting until the syrup's temperature has equalized to a stable maximum or minimum.
- Explains how to take the graduated cylinder with the syrup out of the beaker and place it on a secure spot.
- Recommends repeating steps 4 through 12 five times for all beakers, including ice water, hot water and lukewarm water.
- Explains that the raw data gathered from the experiment will be divided into three groups: warm syrup, cold syrup and lukewarm syrup.
- Recommends using a beaker with 90ml of tap water to heat to 90°c (363.15°k) to avoid burns.
565 wordsRead More - The Solubility Curve of KNO3: Lab Procedurecomparative essay4. Pour about 300mL of tap water into the beaker. Set up a hot-water bath using a hot plate, retort stand, and thermometer clamp. Alternatively, use a Bunsen burner, retort stand, ring clamp, thermometer clamp, and wire gauze.
In this essay, the author
- Explains kno3's solubility curve. draw a sketch to show the shape of the curve, and plot it on the y-axis and temperature.
- Explains how to prepare a data table to record the mass of the solution, the initial volume of water, and the temperatures at which the solutions began to crystallize.
- Explains how to put the test tube inside a beaker for support, set the readings on the balance to zero, and measure 14.0g of kno3.
- Recommends adding one of the following volumes of distilled water to the test tube, as assigned by your teacher.
- Recommends setting up a hot-water bath using hot plate, retort stand, and thermometer clamp.
- Explains how to insert the stopper, thermometer, and wire into the test tube.
- Explains how to place the test tube and thermometer in the beaker and begin heating the water bath gently.
- Recommends removing the stopper from the test tube and adding 5.0ml of distilled water. the solution is now more dilute and therefore more soluble.
- Advises putting the stopper, thermometer, and stirring wire back in the test tube. if crystals have already appeared, begin warming the water bath again.
460 wordsRead More