The exothermic reaction observed in this procedure is as follows ; HCL(aq) + NaOH(aq) ➡ H2O(l) + NaCL(aq) + energy. The purpose of the lab was to determine the value of ∆H of the neutralization reaction above, then compare the data to that of the accepted ∆H value of neutralization to determine the accuracy and validity of our findings. A singular trend was observed and is as follows; the decrease of ∆H indicates a reaction is exothermic, a neutralization reaction results in a (-) value ∴ the (-) value collected was congruent with the trend above, proving our results have some legitimacy at the least. Unfortunately, this lab has a large margin of error and it is possible for a plethora of errors to occur during the proceedings of the lab
that could account for any deviation from the accepted enthalpy value. The weaknesses and limitations of the lab vary in cause and influence; however, their ability to skew results must be taken into account when determining the validity of the data collected. The limitations and weaknesses are as follows: human error when measuring ratios of reactants, instrumental error when measuring ∆H, reactants (HCL, NaOH) reacting with atmosphere prior to the initial reaction, contamination of the provided reagents, and environmental factors affecting the reaction. Measuring errors are common and often devastating to the labs results, to avoid this error multiple measuring sessions could take place or pipettes could be thoroughly practiced to ensure accuracy. Environmental factors were most likely the cause of the deviation of the data collected from the accepted enthalpy value, performing the lab in a pseudo closed system environment is the most effective way to avoid said error. To achieve this nearly fully closed system, the environment must be free off debris to avoid contamination and kept a constant temperature, the reactants must be kept in sealed containers prior to lab to avoid reacting with the atmosphere. The results of the preformed lab where congruent to that of the given value. The Enthalpy value measured (- 56 kj/mol) had .38% deviation from of the accepted enthalpy value (-55.8 kj/mol) ∴ very little error occurred during the procedure, the validity of the data collected is legitimate. The data collected is justified by the equations and calculations used to determine the difference between the enthalpy value determined and the accepted enthalpy value.
The question that was proposed for investigation was: Can the theoretical, actual, and percent yields be determined accurately (Lab Guide pg. 83)?
There were no significant error factors that may have affected the arrangement of the lab experiment. Everything went smoothly with relative ease.
Random and systematic errors are both factors that can affect the reliability and accuracy of the results respectively. As all the graphs contained outliers, and hence, scatter, this indicates that random errors were present. Such errors may result from the inconsistent masses of the Alka Seltzer tablets. As these tablets were cut manually with a knife, it is unlikely that the mass of each half of an Alka Seltzer tablet would be the same. Thus, when using the tablets to react with HCl, the true number of tablets reacting would have not been the same as the number denoted for the trial, and with each repeated trial for the same number of tablets reacting, the reacting mass and ratio would have not been inconsistent. Consequently, the
The purpose of this lab was to calculate the specific heat of a metal cylinder
Possible errors include leaving in the test strips for too long, draining too much water into the aquatic chamber (overfilling/watering), and inverting the tubes for a shorter amount of time than required. Although there are many possible human errors that could be committed in this lab, it is important to note that the tools used for water testing could be expired and could therefore not work as well at detecting the proper levels for dissolved oxygen, pH, and nitrate.
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.
In conclusion the experiment was carried out and had great success proving my prediction to be correct and enabling solid and valid results which were able to be put in a graph. I believe my prediction could have been more accurate or more backed up if I had made a quantitative prediction. Though what I believed would happen did happen during the experiment which helped to understand the graph and the results which led me to be able to write a thorough report on them.
Possible sources of error in this experiment include the inaccuracy of measurements, as correct measurements are vital for the experiment.
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.
One possible source of experimental error could be not having a solid measurement of magnesium hydroxide nor citric acid. This is because we were told to measure out between 5.6g-5.8g for magnesium hydroxide and 14g-21g for citric acid. If accuracy measures how closely a measured value is to the accepted value and or true value, then accuracy may not have been an aspect that was achieved in this lab. Therefore, not having a solid precise measurement and accurate measurement was another source of experimental error.
A precipitation reaction can occur when two ionic compounds react and produce an insoluble solid. A precipitate is the result of this reaction. This experiment demonstrates how different compounds, react with each other; specifically relating to the solubility of the compounds involved. The independent variable, will be the changing of the various chemical solutions that were mixed in order to produce different results. Conversely the dependent variable will be the result of the independent variable, these include the precipitates formed, and the changes that can be observed after the experiment has been conducted. The controlled variable will be the measurement of ten droplets per test tube.
Specific heat capacity of aqueous solution (taken as water = 4.18 J.g-1.K-1). T = Temperature change (oK). We can thus determine the enthalpy changes of reaction 1 and reaction 2 using the mean (14) of the data obtained. Reaction 1: H = 50 x 4.18 x -2.12.
Neutralization Experiment AIM:- To investigate how heat is given out in neutralizing sodium hydroxide (NaOH) using different concentrations of Hydrochloric Acid. Background Information:- Substances that neutralize acids are called alkalis. An acid is a substance that forms hydrogen ions (H+ ) when placed in water. It can also be described as a proton donor as it provides H+ ions. An example of an acid is hydrochloric acid (HCl), Sulphuric acid (H2SO4) etc.
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.