13 Lab Report Conclusion Examples

Lab Report Conclusion Examples

Writing a lab report conclusion is never easy. Picture this, there you are having spent a lot of time in the lab running the experiment to get the perfect data, and then hours to create the perfect lab report write-up. But this is an issue: you do not know what to include in your lab report conclusion to leave an impression that will attract the top grade in class. That is what this article is about. I have marked thousands of papers, and these are just 13 of the recent lab report conclusions that I felt best suited the respective lab reports. 

Investigating the Effect of Buffer Systems on the Rate of Catechol Oxidation

In conclusion, catechol oxidation rates are higher in buffer solutions than in water, confirming the hypothesis that catecholase operates optimally under slightly acidic conditions. In 0.00303 M substrate, initial rates were 0.0014 ± 0.0003 in buffer and 0.0011 ± 0.0002 in water. The rate differences were smaller but apparent in 0.00151 M and 0.000757 M substrate concentrations. The V_max and K_M values for the buffer system were 1.74 ± 0.04 × 10⁻³ M/s and 7.01 ± 0.30 × 10⁻⁴ M, while for water, they were 1.35 ± 0.20 × 10⁻³ M/s and 5.0 ± 2.0 × 10⁻⁴ M. Therefore, the findings suggest that buffered systems should be used when preparing apples, their products, and other fruits with catechol for high-quality salads. The higher uncertainty is caused by a small sample size and potential measurement errors. These results likely represent a lower bound due to possible underestimation of enzyme concentration, overestimation of substrate concentration, or enzyme inhibition.

The Kinetics of Oxidation-Reduction Reaction Between KI and H₂O₂

In conclusion, the aims of the experiment were met since the rate law of the reaction was determined to be Rate=k[KI][H₂O₂] since the order with respect to KI and H2O2 is 1. The overall order of the reaction was determined to be 2, and the value of k 1.12×10^-4 M^-2s^-1. In addition, the activation energy was calculated to be 53.58kJ/mol. The results had relatively high accuracy except for the activation energy, which suggests potential errors in variations of temperature, determination of end-points, and competing reactions. All waste solutions containing iodine, H2O2, and sodium thiosulfate were collected in designated waste containers and emptied in the drain to prevent environmental contamination.

Identification of Unknown Organic Compounds Using Spectroscopy, Melting Points, and Boiling Points

In summary, this experiment aimed to uncover the identities of the unknown solid C and liquid S dumped illegally in Pierce County. Using the C-NMR and H-NMR spectra of the respective compounds, the carbon and proton environment was determined, and the framework was established. The functional groups were determined using the FTIR, where both had carboxyl groups, but only the solid had an aromatic environment. The identity of the liquid was determined as 2-methyl-2-butanol, while the solid was determined as benzoic acid. These assertions were further confirmed by the boiling point range for the liquid, the solid's melting point, and the masses of the abundant fragments, as shown by the mass spectroscopy data. Both of these have some level of toxicity to human beings and the environment and require specialized disposal.

Identification of Components in an Unknown Through Thin Layer Chromatography

In conclusion, TLC is an effective method of separating compounds and identifying them. The aim of the experiment was partly met because one component of the unknown was identified to be acetaminophen. It was also determined that Caffeine is present in Excedrin and Acetaminophen. However, there was an error in the experiment since one spot in the unknown could not be identified and no spot was developed for Aspirin. This could be due to contamination of the unknown, which might have introduced a compound that was not among the standards. Alternatively, it could have been due to incorrect measurements of the spot and uneven development.

The Synthesis of Acetyl Salicylic Acid (Aspirin) and its Characterization Using Different Analytical Techniques

In conclusion, the aim of the experiment was met as aspirin was synthesized by acetylating salicylic acid in the presence of phosphoric acid. The percentage yield was 75.94%, and the melting temperature was slightly lower than that of commercial aspirin at 132-134 °C. The purity of the compound was determined as 91.01% using spectrophotometric absorbance. The purity of aspirin can be increased by using high-purity salicylic acid, enhancing recrystallization by offering more time, sublimation, and through column chromatography.

Investigating the Dissociation Behavior of Calcium Hydroxide (Ca(OH)₂) in Water Across Varying Temperature Conditions

In conclusion, the thermodynamics behind the dissolution of calcium hydroxide in water at different temperatures was observed through calculations of the equilibrium constant, Gibbs free energy, entropy, and enthalpy. The findings were relatively close to theoretical values, indicating great accuracy in the methods. The present deviations can be attributed to improper determination of endpoint, contamination, and poor filtration. This experiment is crucial industrially, especially in water treatment where calcium oxide is used.

Synthesis of Methylbutenes

The purpose of the experiment was partially achieved. As per the objectives, 2-methyl-2-butanol was dehydrated in an acid-catalyzed elimination reaction mechanism to yield 2-methyl-1-butene and 2-methyl-2-butene. The percentage yield was 47.14%, which is relatively good, although it suggests some inefficiencies in converting reactants to products. GC spectroscopy provided an effective technique for separating and identifying the products, providing quantitative data on the relative amounts of each compound. To this end, it was determined that as per Zaitsev’s rule, 2-methyl-2-butene, which is more substituted and hence has a more stable carbocation intermediate, is the major product with a relative composition of 70.62%, while 2-methyl-1-butene has a composition of 5.11%. As expected, the more volatile 2-methyl-1-butene had a shorter elution time, and its peak appeared earlier than 2-methyl-2-butene.  IR analysis of the reactant and product revealed differences in spectra, with a broad peak identified at 3300-3600 cm^-1 for the alcohol due to the OH group and a peak at 1600 cm^-1 for both products corresponding to the C=C bond. The peak intensity was lower in the more substituted 2-methyl-2-butene than in 2-methyl-1-butene.

However, the experiment's aim regarding NMR was unmet due to high levels of impurity in the product. The experiment can, therefore, be improved in the future by using a more rigorous purification technique, such as fractional distillation, which yields a purer product. In addition, the reaction and separation procedures should be conducted in controlled environments to reduce side reactions, promoting the purity of the products.

The Synthesis and Analysis of 2-Bromo-2-Methyl Octane via Nucleophilic Substitution

In conclusion, the aim of the experiment was met, albeit with some errors, because 2-Bromo-2-Methyloctane was successfully synthesized and identified using FTIR and GC/MS. There were some errors in the experiment that led to an unrealistic yield, indicating the purity of the compound was low. This is supported by the GC/MS spectra, which contain some unidentifiable fragments. In the future, this can be avoided by performing the experiment in more conducive conditions to transform more reactants into products and employing a purification technique such as column chromatography, which can separate the products based on their interaction with a polar phase.

Stoichiometry KCIO₃

The experimental findings were relatively good but inaccurate because mass percentages were 36.92% KClO₃ and 63.08% KCl. The experimental values show an absolute deviation of 26.16% from the theoretical values of 50% each by mass. This error can be attributed to the following factors. First, it is highly possible that there was an incomplete decomposition. It is likely that there was an incomplete decomposition of KCIO_3, leading to a lower recorded mass of oxygen and KCIO₃ and a higher mass of residue, contributing to the experimental error. The incomplete decomposition might be due to uneven heat distribution affecting the oxygen released and the change in mass of the residue. Second, inaccurate measurements of the mass of the test tube + MnO₂ + KClO₃ - KCl mixture before and after heating. It is possible that the measurement taken before heating was higher than the actual value or the one taken after heating was lower than the actual value, both of which reduce the calculated mass of oxygen and hence that of KCIO_3, thus the error.

Based on these sources of error, there are two suggestions to improve the results. The first is enhancing the heating techniques using the following modifications. To start with, the test tube should be rotated often automatically or manually to increase the surface area of the contents, thereby distributing the heat more evenly. This would lead to the decomposition of more KCIO₃ improving the experimental findings. Alternatively, a more controlled heat source, preferably a furnace, could be used for better temperature regulation and even heat distribution, improving decomposition. The second suggestion is to conduct the experiment in triplicates. The second error could be eliminated by performing the experiment in triplicate so that the results can be averaged and outliers removed to minimize the random errors. This reduces the impact of measurement errors.

Separation and Identification of Compounds using Thin Layer Chromatography

The aim of the experiment was to perform a TLC experiment and observe how various functional groups aid separation through chromatography, identify an unknown compound, and determine the purity of compounds separated through extraction. This aim was met because aspirin’s Rf value was determined to be 0.78, followed by acetaminophen’s 0.73 and ascorbic acid’s 0.51. This aligns with theoretical concepts that show ascorbic acid is the most polar due to multiple hydroxyl groups, followed by acetaminophen, which has hydroxyl and amide groups, and then aspirin, which has carboxyl and ester groups. Due to the similar Rf value under identical conditions, the unknown was determined to be aspirin. Focusing on the purity of the separated compounds, it was observed that three spots were formed where two were expected, suggesting the presence of an impurity. The experiment's success can be attributed to an excellent spotting technique and the use of a suitable solvent, which ensured the separation of the molecules based on their polarities. The experiment can be improved by running duplicates and experimenting with different solvents to observe the effect of a solvent on effective TLC separation.

The Synthesis of Acetyl Salicylic Acid (Aspirin) and its Characterization Using Different Analytical Techniques

In conclusion, the aim of the experiment was met as aspirin was synthesized by acetylating salicylic acid in the presence of phosphoric acid. The percentage yield was 75.94%, and the melting temperature was slightly lower than that of commercial aspirin at 132-134 °C. The purity of the compound was determined as 91.01% using spectrophotometric absorbance. The purity of aspirin can be increased by using high-purity salicylic acid, enhancing recrystallization by offering more time, sublimation, and through column chromatography.

Identification of Unknown Compound #114

In conclusion, the functional group in the unknown compound #114 is a carboxylic acid based on its solubility in water and sodium hydrogen carbonate, and supported by the lack of formation of a colored complex with Ferric chloride. The identity is 3-Hydroxybenzoic acid, which has a melting point of 201 °C, which differs from the observed value by 3°C, and an equivalent mass of 138.1, which is within close proximity to the calculated 140.14.

Concentration of Quinine

In conclusion, this experiment aimed to determine the excitation wavelength of quinine and its concentration in tonic water and determine the effect of matrices and quenchers on emission. The aim was met because the excitation wavelength of quinine was determined to be 346.28 nm. The concentration of quinine was calculated to be 29 ppm, indicating an error in the measurement of standards. In addition, the quenching effect of halides was confirmed through KI’s suppression of emission intensity.