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
Thermodynamics is essentially how heat energy transfers from one substance to another. In “Joe Science vs. the Water Heater,” the temperature of water in a water heater must be found without measuring the water directly from the water heater. This problem was translated to the lab by providing heated water, fish bowl thermometers, styrofoam cups, and all other instruments found in the lab. The thermometer only reaches 45 degrees celsius; therefore, thermodynamic equations need to be applied in order to find the original temperature of the hot water. We also had access to deionized water that was approximately room temperature.
There were no significant error factors that may have affected the arrangement of the lab experiment. Everything went smoothly with relative ease.
Every time the container the substance is in is opened some of it will evaporate, causing the temperature of the liquid to change. As it evaporates, the temperature decreases.
The data we gathered was tested to be as accurate as possible. Our prediction on the solvents did not support our data that we collected. The cause of this could be due to human error when washing the beets or the cutting of the beets. The beets were not perfectly cut the same size, so some beet pieces were bigger than others which can affect the final the final result. We followed each step and followed the time limits cautiously. I can say if we were to redo the experiment our results would be similar because we would attempt to do the experiment as close as we did the first
Discussion: The percent of errors is 59.62%. Several errors could have happened during the experiment. Weak techniques may occur.
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 was found by dividing the heat transferred by the mass times the temperature change (Cp=Q/m x ΔT) of all three trials. Then the specific heats of all the trials and divided that by the number of trials (three). All of the specific heats add up to 1.07 and 1.07 divided by three equals 0.36, the average. The average percent error of the experiments is 7.7% because all of the percent errors from the trials added together equals 23 and 23 divided by three equals
In this experiment, there were several objectives. First, this lab was designed to determine the difference, if any, between the densities of Coke and Diet Coke. It was designed to evaluate the accuracy and precision of several lab equipment measurements. This lab was also designed to be an introduction to the LabQuest Data and the Logger Pro data analysis database. Random, systematic, and gross errors are errors made during experiments that can have significant effects to the results. Random errors do not really have a specific cause, but still causes a few of the measurements to either be a little high or a little low. Systematic errors occur when there are limitations or mistakes on lab equipment or lab procedures. These kinds of errors cause measurements to be either be always high or always low. The last kind of error is gross errors. Gross errors occur when machines or equipment fail completely. However, gross errors usually occur due to a personal mistake. For this experiment, the number of significant figures is very important and depends on the equipment being used. When using the volumetric pipette and burette, the measurements are rounded to the hundredth place while in a graduated cylinder, it is rounded to the tenth place.
the water baths I think were accurate enough but having two thermometers in each bath maybe would have helped to hold the temperature readings more accurately. We were not given any instructions either to shake or not to shake the test tubes with the coloured solutions before inserting them in the spectrophotometer to read the absorbance. By shaking each test tube a certain number of times before putting it in the spectrophotometer could have improved the accuracy of the absorbance of the solutions.
The first law of thermodynamics simply states that heat is a form of energy and heat energy cannot be created nor destroyed. In this lab we were measuring the change in temperature and how it affected the enthalpy of the reaction.
A calorimeter is used to measure the quantity of thermal energy gained or lost in a chemical change. For this experiment, a “coffee cup” calorimeter (a Styrofoam cup with lids and a thermometer) was used, under constant volume and atmospheric pressure. However, this calorimeter does not retain all the heat as it is not the most optimal choice for a calorimeter, but for this experiment, it is assumed that there is no loss of heat. In relation to heat, one method is to measure the thermal energy is to measure the specific heat capacity of the substance, which is essentially the amount of thermal energy needed to heat one gram of the substance by one degree.
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.
There is also the potential of human error within this experiment for example finding the meniscus is important to get an accurate amount using the graduated pipettes and burettes. There is a possibility that at one point in the experiment a chemical was measured inaccurately affecting the results. To resolve this, the experiment should have been repeated three times.
Possible sources of error in this experiment include the inaccuracy of measurements, as correct measurements are vital for the experiment.
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.