This lab has a typical percentage error usually around 30%-40%. By looking at the percentage error of the calculated enthalpy and entropy, the percentage error is large but small when compared to the typical percentage error that is usually found in the lab. This typically large percentage error shows that there is an error in this lab that causes the experimental data to be less than the theoretical data. In this lab there were many opportunities that an error could have occurred and skewed the data. One such error could be in the difference in temperature for trials 1 and 2. Although there was a short window between the trials for the Borax solution in an ice bath, but in this time the temperature could have changed a couple of degrees. …show more content…
The Borax Lab also deals with concepts such as the relationship between enthalpy(▲H°), entropy(▲S°), temperature, and Gibbs Free Energy(▲G°). This relationship is integral to the understanding of this lab as it influences how the influence of temperature affect the flow of energy in a system. As a substance is heated or cooled, the enthalpy, also known as the total heat content of a system, will either increase or decrease respectively if there is constant pressure and volume. This change in temperature also has an effect on the entropy, also known as the disorder of a system. As the substance is heated or cooled, the entropy of the system increases or decreases respectively. As these two aspects of energy in a system come together, along with the temperature of the system, to find the total amount of energy that can be used to do work, also known as Gibbs Free Energy. Gibbs Free Energy is important in understanding the change in energy that occurs in a system and whether the change in energy that occurred has left the system in equilibrium. Finally, the Gibbs Free Energy can show the spontaneity of a …show more content…
The molar solubility of Borax at a room temperature of 23.5°C for trial 2 was 0.00941 M. The average value for molar solubility of Borax at room temperature of 23.5°C was 0.00941 M. The molar solubility of Borax in an ice bath of 9.4°C for trial 1 was 0.00140 M. The molar solubility of Borax in an ice bath of 9.4°C for trial 2 was 0.00129 M. The average molar solubility for Borax solution in an ice bath of 9.4°C was 0.00135 M. The values for the molar solubility for the Borax solution at room temperature was very precise to the point where both values equaled 0.00941 M. The values for the molar solubility for the solution of Borax in an ice bath was not as precise with a distance in between the values of 0.00011 M. The enthalpy of the Borax solution was calculated to be 95.86 kJ/mol. The Gibbs Free Energy of the Borax solution at room temperature of 23.5°C was calculated to be 13.89 kJ/mol. The Gibbs Free Energy of the Borax solution in an ice bath of 9.4°C was calculated to be 11.49 kJ/mol. The entropy of the Borax solution at room temperature of 23.5°C was calculated to be 284.55 J/mol*K. The entropy of the Borax solution in an ice bath of 9.4°C was calculated to be 290.26 J/mol*K. The average entropy change of the Borax at room temperature and the Borax solution in an ice bath was calculated to be 287.41
First, the freezing point depression of magnesium chloride was found. To begin, an ice bath was created in a 600 mL beaker filled with ice provided in the laboratory and rock salt. Next, Four different solutions with concentrations of 0.0 g (control), 0.2 g, 0.4 g, and 0.6g of magnesium chloride and 15 mL of deionized water were created. Each solution was made in a 100 mL beaker. The solutions containing magnesium chloride were stirred with a glass rod until the salt was completely dissolved. All equipment was cleaned with deionized water to minimize cross contamination. To calculate the freezing point, a Vernier temperature probe provided in the laboratory was used. The temperature probe was plugged into the GoLink!
Possible sources of error in this experiment include the inaccuracy of measurements, as correct measurements are vital for the experiment.
We started by testing the time it takes for sugar cubes to dissolve in boiling water. We boiled the water to 100℃ and then dropped four sugar cubes in, each cube took exactly 1:03 to dissolve. After testing the boiling water we switched the beakers, which we kept the same size and filled it with room temperature water. We made the room temperature 22℃ and then dropped four new sugar cubes in, this time it took the cubes precisely 4:52 to dissolve, so lastly we tested cold water temperature. Again switching
In order to better understand this experiment, one must first have a clear understanding of several underlying concepts. First, one must be aware of the ingredients and properties of Gatorade. Secondly, one must understand what an electrolyte is and its biological significance. Thirdly, one must be familiar with the general idea of conductivity. Finally, one must understand how freezing a substance affects its properties at a molecular level. Once a basic understanding of the aforementioned concepts is obtained one will be able to adequately conduct the experiment and
Going into details of the article, I realized that the necessary information needed to evaluate the experimental procedures were not included. However, when conducting an experiment, the independent and dependent variable are to be studied before giving a final conclusion.
This is expressed as Δ +ve (delta positive). If the total energy put in is less than the energy created, then the substance warms up (it is exothermic). This is expressed as Δ -ve (delta negative). I will investigate eight different alcohols using an alcohol or spirit burner, to measure the energy change during burning by measuring the change in temperature of some water held in a container.
The factors that effected my results, that I couldn’t control the temperature of water, room temperature and. because I carried out my investigation on different days, so on the different days, the temperature will also be different. I could control temperature by carrying out the experiment on the same day, so the temperature will be the same.
consistent with the same reaction rate throughout the experiment. The average rate of reaction for the endotherms was 7.90 mL/sec and the endotherm had a higher standard deviation which shows it less reliable since the data points are spread unevenly. The standard
Introduction The objective of the experiment is to utilize a calorimeter to observe the changes of thermodynamic quantities. For Part 1: Heat of a Neutralization Reaction, 50.0 mL of 2.0 M NaOH was added and mixed with 50.0 mL of 2.0 M HCl in a calorimeter to in order to calculate the heat of neutralization for a strong acid/strong base reaction. For Part 2: Specific Heat Capacity of a Metal, an unknown metal (either A, B, or E), was heated in boiling water, and the unknown metal was placed and mixed in a calorimeter with cold tap water, and the unknown metal was identified. For Part 3: Molar Heat of Solution of a Salt, ammonium chloride salt (NH4Cl) was added and mixed in a calorimeter with deionized water, and the molar heat of solution
Introduction According to the Columbia Encyclopedia, sodium tetraborate decahydrate (also known as borax) is a chemical compound that is slightly soluble in cold water but very soluble in hot water (“Borax”). Some of the various uses of borax are a cleansing agent, an antiseptic, occasionally as a preservative and used as a flux for silver soldering. The purpose of the experiment was to determine the thermodynamic quantities, enthalpy (ΔH°) and the standardized entropy (ΔS°) of the solvation of sodium tetraborate decahydrate, borax, in water. This was achieved by observing the effect various temperatures have on the solubility product of borax.
Thermochemistry is the study of energy changes that occur during chemical reactions and changes in state. There are two different processes that have to do with the absorption and release of heat. In the endothermic process, the system picks up heat, as the surroundings lose heat. In the exothermic process, heat is released to its surroundings. Heat either goes in or goes out.
In order to make this experiment a fair test, I changed only one input variable, the temperature. I kept the amount and concentration of the liquids the same (20m...
In both tests the results show very different things. I think the second test was a lot more successful than the first. The main factor that would have overall affected the results would have been the different temperature between the two tests. This and the fact that they were on a different day and the fact that we didn’t have the exact same amount of bugs in the containers would have been the biggest factors that would have disadvantaged our test.
Thermostats are a usual method of sensing a temperature of a system and maintain the system’s temperature at a predefined point. The most popular and ubiquitous appliance in any home is a Refrigerator. A thermostat maintains the pre-set value of temperature by switching the heat conduction. In short, it regulates the heat flow. In Physics, there is no such thing as cold, its either higher temperature or lower temperature – heat flow (absorption or dissipation). Thermostats are a regular feature in Air Conditioner, Microwave Ovens, Ironing machines, Induction Heaters and Refrigerators in home appliances category. At the same time in many scientific labs (biology, physics or chemistry research domains) storing experimental samples (veils, substrates, materials etc.) these above appliance have a larger role to play. Most of these laboratory experiments run for weeks and such appliances run almost 24x7. Maintaining the pre-set temperatures are an integral part in such labs.
Thermodynamics is the branch of science concerned with the nature of heat and its conversion to any form of energy. In thermodynamics, both the thermodynamic system and its environment are considered. A thermodynamic system, in general, is defined by its volume, pressure, temperature, and chemical make-up. In general, the environment will contain heat sources with unlimited heat capacity, allowing it to give and receive heat without changing its temperature. Whenever the conditions change, the thermodynamic system will respond by changing its state; the temperature, volume, pressure, or chemical make-up will adjust accordingly in order to reach its original state of equilibrium.