The Heat Capacity Of A Calorimeter

The purpose of this experiment was to determine the heat of combustion of magnesium using Hess’s Law. This experiment was significant in understanding how heat can be absorbed or released and how using a calorimeter can help measure heat flow. Part A of this experiment used two dry Styrofoam cups and a magnetic stir bar to create a calorimeter. Temperature was measured and distilled water was placed into the calorimeter, and after 2-3 minutes, boiling water was mixed in. The computer continued to take data for 6 minutes and then the calorimeter was reweighed and emptied. Part B and C were the same, only using two different types of magnesium (magnesium ribbon (part B) and magnesium oxide (part c)) instead of the boiling water. The major result is that all of these experiments release energy because the calorimeter temperature increased.

In order to measure the heats of reactions, add the reactants into the calorimeter and measure the difference between the initial and final temperature. The temperature difference helps us calculate the heat released or absorbed by the reaction. The equation for calorimetry is q=mc(ΔT). ΔT is the temperature change, m is the mass, c is the specific heat capacity of the solution, and q is the heat transfer. Given that the experiment is operated under constant pressure in the lab, the temperature change is due to the enthalpy of the reaction, therefore the heat of the reaction can be calculated.

To improve the experiment, the methodology could be improved by having an efficient calorimeter to retain as much heat as possible, rather than just a tin can. Additionally, more trials for each of the experiments could be conducted to ensure correct and precise data is collected to determine more accurate conclusions.

The heat capacity per unit mass of a body, called specific heat capacity or more simply specific heat, is used to more directly compare the heat capacity of substances. Pure water has high specific heat capacity that is exactly 1 calorie per gram, whereas other common substances have much lower specific heats. The reason is because it takes more energy to increase the kinetic energy of hydrogen-bonded water molecules than it does for substances in which the dominant intermolecular interaction is the much weaker van der Waals force. As a result, water gains or loses much more heat than other common substances while undergoing an equal temperature change.

The lab used methods of calorimetry in order to measure the temperature change of reactions and calculate the changes in

50mL of 2M NaOH was added to the two stacked Styrofoam cups in a 400mL beaker. The cup was then covered with a plastic lid and a temperature probe was inserted through the lid and into cup in a way so that it did not touch the bottom. 3-4 temperature readings were then collected by clicking “collect” on LabQuest to start Run 2, and initial temperature was determined. 50mL of 2M NH4Cl was then added to the NaOH solution in the cup and swirled around. The rest was repeated from the first

The results of each mixture were averaged out and the heat given out and the heat given off in KJ/g was measured by the heat formula Q = mc ΔT. The theoretical values were calculated using a mass fraction. The heat given off was measured using a calorimeter of water and how much heat it absorbed. The theoretical values were calculated by using a mass fraction. The prediction of this experiment was that the alkanes that had longer carbon chains would increase the amount of heat given off.

The instrument used to measure temperature is a thermometer. There are many types of thermometers; the most common consist of a closed, graduated glass tube in which a liquid expands or contracts as the temperature increases or decreases. Many different types of thermometers work by detecting changes in the volume or pressure of an enclosed gas or by registering thermoelectric changes in a conductor (such as a thermistor or thermocouple). Galen, a Greek scientist and doctor made the first attempt at measuring temperature.

One thing we struggled with was that each flame had a different height. Some were very short and others were quite tall. We ended up doing our experiment over because the stands were all at different heights and we couldn’t be sure that we had accurate results. To fix that we redid the experiment but there was probably still mistakes in the way that the heat was transferred. Another possible error was that we could not do this experiment inside of a calorimeter because it used a flame. It was very much an open system and mass could evaporate since heat was radiating out. These mistakes would all make our results too low because heat would escape and so the change in temperature would be smaller than the actual temperature change, which is multiplied by other values to get the heat given off of the flame. Thus, the final number would be smaller than it would theoretically be in an isolated

For the first trial 100 mL of distilled water was poured into a 500 mL beaker and placed on a hotplate to warm to 40 °C. While waiting for the distilled water to warm to the desired temperature, two sponge animals both red and blue were selected and weighed on the scale for their beginning weight individually. After some time elapsed, the water temperature was measured with a stirrer thermometer, which was observed to never touch the bottom of the glass beaker. After the water was warmed to the desired temperature, 50 mL of the water was poured into a graduated cylinder, and then poured into the Styrofoam cup. The remaining liquid was then poured into the graduated cylinder, and then poured into the remaining Styrofoam cup.

The Fahrenheit scale was invented by a German physicist named Daniel Gabriel Fahrenheit who the scale was named after. In 1714 the first modern thermometer as developed which was the mercury thermometer with more advanced measurements than all of the other thermometers created. The original Fahrenheit scale was not entirely accurate because it did not give an accurate calibrate. The Fahrenheit temperature scale ranged from 212 degrees (boiling point of water on this scale) to 32 degrees (boiling point on

Originally it was planned to cover the calorimeter and heat shield with foil to insulate heat. This idea was used throughout the experiment but in different ways. Then used a circular piece of styrofoam over the heat shield and taped insulation tape around it and the heat shield as a lid. By this point a water calorimeter found better results compared to a copper block calorimeter. Using a copper calorimeter usually provides more accurate results and lower percentage errors.

We will be using 6 different fuels to heat up 100ml of water, and find out the changes of the temperature. We will measure the temperatures of the water before and after the experiment. We will burn heat the water for exactly 2 minutes, and check the changes in temperature. The change in temperature will allow us to work out the energy given off the fuel by using this formula:

The Effect of the Surrounding Medium of a Fluid on its Rate of Heat Loss was conducted by the experimenter. The sciences behind the investigation include the five primary methods of heat loss and the characteristics of the fluid encompassing mediums such as being good conductors of thermal energy and having low emissivity. The purpose of the experiment was to establish the best medium for sustaining the temperature of a fluid. The experimenter hypothesized that if a liquefied substance is placed in Styrofoam, metal, glass, and thermoflask medium, then the substance’s rate of heat loss will be slowest in the thermoflask medium. To conduct the experiment, the investigator poured 90 degrees Celsius water into the four mediums, Styrofoam, metal, glass, and thermoflask, then recorded the temperatures after 30 minutes. The result temperatures were divided by 30 to calculate the degrees Celsius lost per minute. The hypothesis turned out to be correct with thermoflask losing heat the slowest at a rate of 1.01 degrees Celsius lost per minute. The glass medium had the fastest rate of heat loss at a rate of 1.26 degrees Celsius lost per minute. There was an explanation behind why the results came out the way they did. According to the Stefan-Boltzmann law, materials with low emissivity lose radiated heat slowly. Thermoflasks have a low emissivity which gives reason to why the thermoflask was more efficient at sustaining a temperature of a fluid. The glass’ speedy rate of heat loss was

Aim: The aim of this experiment is to determine the properties of two unknown metals by heating them up to their initial temperature and then determining their specific heat capacity by calculating the temperature difference once it reaches equilibrium with a room temperature water bath. Therefore comparing the two metals with their specific heat capacities on a known table and deducing the unknown metals. The water bath needs to be well insulated so that no heat is exchanged with the surroundings and it needs to be ensure that the metal block is heated thoroughly.